Hi all,

Before adding this to pebuilder I want some of you to test if this also works on your hardware.
Please note that these instructions assume you know your stuff...
TRYING THIS IS AT YOUR OWN RISK!

The hardware I used was a kingston 512MB USB Flash disk and a hp/compaq Desktop D330 PC

Installing BartPE to USB Flash Drive (UFD)
Generate the BartPE files, using PE Builder, just as you would when you wanted to create a bootable CD, only there is no need to create an ISO image.
From a windows XP/2003 system, connect the UFD to your system, check what drive letter the device is using.
Your UFD must be formatted with FAT. If not format it using: "format r: /fs:fat" (where r: is the drive letter of your UFD)
Your UFD must not use some kind of protection or secure options!
Your BIOS must support booting from UFD.

You must patch the FAT bootsector, see image.
Start de tiny hexer (http://www.mirkes.de), select "file", "disk", and "open drive"
Select the drive for your UFD, for example "\\.\r:"
Click to view attachment
Select "file", "disk", and "write changes" to save your modifications.

If your UFD uses partitions (mine does) check if the partition is set active.
Start de tiny hexer (http://www.mirkes.de), select "file", "disk", and "open drive"
Select the physical drive for your UFD, mine is at \\.\PHYSICALDRIVE1
Check that the byte at offset 1BEh is set to "80", see image
Click to view attachment
Select "file", "disk", and "write changes" to save your modifications.

Start peinst.cmd (http://www.nu2.nu/tmp/peinst.zip)
Select option 1 - Set the source path to the location of your BartPE files, for example c:\pebldr
Select option 2 - Set the target path to the UFD drive letter, for example r:
Select option 5 - Install BartPE and select option 1 - Install BartPE files. Copying takes a few minutes...
Done, try booting the UFD.

I still get the dreaded stop 7B after the splash screen...

Interesting points - both drives I used ( a 512 and a 256 ) already had the correct values in the boot sector...

Also, I noticed your boot sector was slightly different in other areas i.e.
0x017B-0x0198 I have " key to boot from floppy"

Both formatted as fat, no security, etc normally I can boot from either drive using syslinux or msdos anyway, I shall keep trying if I think of something different....

npropanol

@npropanol

stop 7b, NT did not find the boot device... Maybe bios related, lastest BIOS?
Using winxp/sp1a?



Was the code in the MBR the same?

Bart.

Hi Bart,
i am also trying to get WinPE booting up a USB Stick, cause I saw it on the damn Winhec.First tries I did were doing an Image from an HDD installed WinPE I copied to the stick and this one booted up til the splash screen.Now I am using your method and first of all when formatting the stick with fat under xp or winpe it shows up that the entries (bootsector 0-63) you said should be changed are as they should.Then copying the WinPE files to the stick and try booting results into an error that txtsetup.sif is not found.
I heared at Winhec that only some sticks are able to boot WinPE (so they did it with Lexar sticks), maybe Kingston got the same layout in there sticks.I just have a no name stick at the moment.
So this was done by using a WinPE build from XP SP2 and the tools from MS and hardcoded stuff i am using.
I did the same with PeBuilder and XP SP2 results in could not find biosinfo.inf.

Did it with SP1 and the same error could not find biosinfo.inf.

What i found is that when I am doing a HDD PE install i dont have any files in the root of the drive.

And there were 2 points MS told me to get it booted up the USB Stick.
the first was use LEXAR sticks
and the second that they patched the NT Loader .

but i will keep on trying.

dicht

@dicht

Looks like you got the files in the wrong place or so...
There should be only a few files in the root.

Some thing like this:
\minint
\ntdetect.com
\ntldr
\programs
\winbom.ini
\minint\bartpe.tag
\minint\biosinfo.inf
\minint\explorer.exe
\minint\Fonts
\minint\inf
\minint\ntdetect.com
\minint\Profiles
\minint\setupldr.bin
\minint\spcmdcon.sys
\minint\system32
\minint\txtsetup.sif
\minint\winbom.ini
\minint\WinSxS
...
\programs\A43
\programs\bartpe.tag
\programs\bst5
\programs\Nu2Menu
\programs\pehdinst
\programs\snapshot
\programs\A43\a43.dat
\programs\A43\a43.exe
...

Hmm... they patched ntldr? I wonder what they changed...

Regards,
Bart.

Hi Bart,
i will spend some more time on this soon, but at the moment i have to program stuff for my company.
The files are all in the right place, i will check some other usb sticks.
dont ask me what they patched , but i talked to the main guy for winpe on winhec and when he comes to visit us i hope he brings the tools and the patched nt loader.

dicht

Did you speak to Mr. Miller?

Regards,
Bart.

@bart
No luck here either. I used Lexar 256 stcik on IBM ThinkPad. Message said something like "Disk Error, Press any key to reboot". No indication that an OS was found. I too noticed that my stick already had all of the "patches" by just doing format on XP. Not sure if this was because I had previously attempted to ghost to it or because I used Fixboot/Fixmbr commands. I did not check other locations in the boot record to see if they matched yours.

Hi,
the message disk error press key to continue you get when you have the wrong settings in your bios. In most bios that support booting from usb you can change the settings for what it should emulate at boot time.so it seems that your bios is that to something wrong, set it to auto or try set it to fdd.Then it should begin to boot.

dicht

@dicht

I checked the BIOS and I don't see any way to change emulation. Maybe new BIOS needed. I did try the same UFD on a HP Compag d530 with same results:

Attempting Boot from USB device

Disk Error
Press any key to restart

I have a couple more sticks I am going to try.

EDIT

I rebuilt using a 512 Lexar JumpDrive 2.0 Pro stick using and I get the following:

Attempting Boot from USB device
Error Loading Operating System

This was using the above mention HP. By the way, my 256 stick was also a JumpDrive 2.0 Pro. FWIW, I did take a 64 MB Kingston drive, loaded it with FreeDOS and it booted fine on the HP.

@bart

Just wanted to let you know that the USB sticks that I built and failed to get running were built using PEBuilder 3.0.25. Since it didn't look like I was ever getting to the point of loading an OS, I am not sure it made a difference. It may make a difference trying to complete the boot up. I will try again Monday with the latest pebuilder.

@Bart

My bios is up to date & I am otherwise able to boot from usb devices using syslinux, or msdos...I have tried both USB-ZIP and USB-HDD settings.

I am using XP Sp2 v.2162...

Yes, the code looks the same from what I can see....

I was thinking there needs to be something in one or more of the
[storage files sections] or other
[Hardware id sections] in txtsetup.sif pertaining to usbstor.sys, device id, etc.

I will see what I can see...


npropanol

@bonehead_coder

If you get "Disk Error, Press any key to reboot" that there is a big change that the BIOS is addressing the wrong drive. For example my asus mainboard is set to "auto" by default and emulates fdd when UFD is <530MB and emulates hdd when >=530MB, I had to force it to hdd emulation...

But my Asus PE800SE gives a 7b stop error after the GUI. (NT is not seeing the UFD by driver)

A newer version of pebuilder will not help you!

Error Loading Operating System? That's strange this mean that the BIOS did read the MBR but faid to read the LBR... ?!?

Regards,
Bart.

hi bart,

I am trying to get ufd to work and kind of understand what I have to do.
But could you explain the following

Start peinst.cmd (http://www.nu2.nu/tmp/peinst.zip)

I have downloaded this but when it is run it asks for mkbt.exe which I do not seem to have.


BTW - I think BartPE is the most useful and interesting thing I have ever used.

thank you!

gary brouwer - sydney australia

@garybrobro

Re-download peinst.zip I have added mkbt.exe to it...

Regards,
Bart.

Using a SanDisk Cruzer Mini 512MB USB Stick on two different PCs:

Dell Optiplex GX270 and Dell Latitude D600 - both with newest available BIOS from Dell.

Both systems receive the error posted above - Disk Error Press Any Key To Restart.

I read the explanation above that it has to do with the way the BIOS handles the USB emulation. I suspect this might work if I had a stick larger than 512MB, but money prohibits that.

Just wanted to include my trial of this method. If you come up with another test or something, I'd love to try it. If Dell comes out with a newer BIOS that fixes this problem, I'll come back & post again

Following through this post, I had the same results as most others. Disk error.

Kingston 256MB DataTraveler
On some computers that have Windows 9x, this stick is identified as a Lexar and works fine, so I think the chipset is probably the same as Lexar.

The process was easier because it had already been set up for booting previously.
I reformatted, though, using format f: /fs:fat just to be on-track with the instructions.
Using TinyHexer, I checked the referenced values and they were all as they were supposed to be.
Like npropanol, I noticed differences, but I named my FAT volume "KINGSTON". Would that show up here and account for differences here?

When booting, I got disk error.

Went back and ran the boot.ini util but no difference. Here's my boot.ini:
f:\peboot.bin="Boot BartPE (by PE Builder)"
Since booting will probably not identify the USB volume as "F:", I don't see how this can work.
However, getting the disk error says I never made it far enough to even read Boot.ini yet, right?

For those feeling out of their depth, here's two great links:
Chapter 6 - Troubleshooting Startup and Disk Problems
Forensics: Understanding Partition Recovery Process

I think the second one is best.

I have tested the boot with:

Asus P4P800 SE BIOS 1004
SanDisk Cruzer Mini 256 MB
Windows XP SP1 spanish

The system begins the boot but when the message “Bart PE” is displayed I get “insert disk 2 …. Windows XP”

Regards,

I strongly suspect that the reason many are having trouble must be the BIOS code. Maybe that's why Dell says the USB boot utility they offer only works on 64MB and 128MB sticks.
My Kingston DataTraveler was attempted on two Dells:
Dimension 2400 (bought Jan 2004)
Latitude D800 (bought Mar 2004)

Both boot to DOS USB sticks okay.
I have one 128MB DOS stick and one Dell(Lexar chip) 64MB DOS stick. Each works on each PC.
Just can't get PE to boot. Every reference I've looked at says my boot code is correct.

This is slightly OT but although I get the 7B with PE, I have been able to successfully multi-boot various other goodies in both image form and by bootsector using syslinux and/or syslinux and memdisk. Syslinux will even load the pe bootsector (all the way to the 7B). It has been cool with most everything I can throw at it except of course CD boot sectors...

I have been stuck trying to get it to "skip" and boot from the local disk -
There is not really an equivalent to "localboot 0x80"



npropanol

I got this working on a 256 HP drive key. I was also getting the "Disk error" message so I went out to hp's site and downloaded their disk key formatter.

It is working everytime now! Try this on another type of key:

http://h18007.www1.hp.com/support/files/hp...load/20306.html

Thank you very much bart! This is kick ass.

I booted my Kingston to PE.

The utility scAn refers to formats FAT, FAT32, or NTFS.
It gives a choice between non-bootable or DOS-bootable (demands bootable DOS source - I used a Win98 floppy).
When done, you end up with a USB stick that boots the stick to C: in DOS (just like a dozen other utilities out there).

If you then run Bart's USB installer, you still end up booted to DOS; the PE installer boot files are ignored.

I tried to use Tiny Hexer to edit the bootsector, but it wouldn't let me. So I used DiskProbe (from Windows XP Support Tools).
Per Bart's instructions, the jump was EB 3C 90.
050, 051, and 053 needed changing to 38 4E 24 7D.

I ran Bart's installer to USB but the stick wouldn't boot. I can't rule out that I made an error at some point. I was stuck with the underline cursor blinking in upper-left corner of screen.

Then I booted to the WindowsXP CD, went into Recovery Console, and ran FIXBOOT and FIXMBR on the stick. (After failing to boot from Bart's instructions, I resorted to this to no avail.)

After that, it booted.
I've tinkered with BOOT.INI, but it's obviously not part of the boot process because none of my changes cause it to fail to boot.
This wasn't a smooth process for me, but it worked.

We need to all mention these details when posting:
1) Motherboard chipset
2) Brand/model of USB stick
3) exact processes

My motherboard: Intel 82801DBM (In Dell Latitude D800)
USB stick: Kingston DataTraveler

I now need to take snapshots of my bootsector and MBR, reformat, and follow Bart's instructions again, and compare what worked to what didn't.
There have apparently been several that have succeeded and then we never hear from them again. While these lucky individuals were successful, there seems to be no one yet who fully understands all the nuances of why some work and some don't. I hope I can help figure out exactly what is needed so Bart can script it or program it.

@JeffO and @scAn

Would you guys be so kind as to mail me a copy of your peboot.bin and txtsetup.sif from your working disks (and the disk size)? That would be the fastest way for me to get this working!!!

Thanks!

npropanol

Upon arriving at home, I tried my Kingston in my Dimension 2400.
I got BSOD B7.
This seems to confirm that it is dependant on the BIOS.
So my Kingston will only boot to the Latitude D800 laptop, at this point.

On the exact same Kingston 256MB stick, after looking at the hex on several bootsectors, there seems to be an aweful lot of differences. I suppose there might be several ways to program the bootsector and still have it work, and that some will be more versitile or robust than others?

@scAn
Can you confirm your stick is portable to other systems?

@npropanol
Will try to email you the working files, but it took me about 15 minutes just to get this page up. Not sure if my connection is bad, or 911cd.net is slow. I'll give it a try.

@JeffO

If you first have a Dos LBR and MBR you need to reformat it to NT, "format x: /u". I'm not sure how you can fix the mbr other then recovery console "fixmbr".

Regards,
Bart.

Hi Freax,
after trying and trying , now I am coming up to the Splash screen and then got an 0x0000007b.I am using an no name stick 512mb.

the first tries were just format fat and copying the files, if then the bios stood on hdd emulation i got an disk error, if bios was on fdd emulation i got an could not find biosinfo.

then i used this tool from hp scan talked here formatted with this tool the stick copyied the winpe files and i came up to the splash screen where it show the windows xp logo with the blue scroll bar (bios was on hdd emulation).

So i think hps tool is doing something different than an normal format x: /fs:fat.I think there tool is partitioning the stick.

Will now try partitioning and formatting.

dicht

Hi,
now it gets clearer.
the No Name stick bootet without BOSD 0x0000007b on an MB with Award Bios (set to HDD Emulation).On AMI Bios Boards i get an BSOD.
But it also just works when formatting with that tool from HP (dont know why).

dicht

Bart you maybe know what HPs tool is doing , cause there comes a short message when using about partitioning the stick then its just formatting FAT.

In the USA, there's a saying: There's more than one way to skin a cat.
i.e. There's usually more than one way to do anything and some ways better than others.

The WindowsXP source CD has a file named BIOSINFO.INF. I'm not sure what this is exactly but it reads almost like a high-level BIOS-extension file. There are other INF files, plus other BIN files that look like they add Windows-specific BIOS extensions.

I confess I don't really know what PEBOOT.BIN does. Is it a BIOS-extension? An OS-loader?

I wonder if what we need to stop the 0x0000007B could be accomplished with an INF file? Or an INF+BIN file?

I did not choose DOS bootable. I just chose to format the key. I only have HP machines. I can boot the key on D530's, D510's, NC800's, and NC8000's. Those are the machines I have tried it on and they all boot.

The steps that I took on a Compaq D530 were:

1) Downloaded the HP format key. Selected the default options without the "create a DOS startup disk". Hit Start
2) Opened the key using Tiny Hex. All I needed to change was the partition to active(the 0001 to 8001).
3) Ran peinst and pointed to the e: drive to install to.
4) Booted the D530 from the USB.

I can recreate this everytime on the HP 256 USB key.

@JeffO peboot.bin is the bootsector please send to:

dimethyl_ethyl_ether(at)hotmail(dot)com of course replace characters as needed.

txtsetup.sif lists the hardware ids & driver locations to load...

(personally I think txtsetup will hold the key...)

@npropanol
Check your mail.

I didn't know the bootsector was ever visible in file browser-view. This is confusing, but good I finally got this made clear.
When I load peboot.bin into TinyHexer, it isn't the same as when I "open drive" then choose my USB key "\\.\G:" drive. There are differences starting at 03E and continueing thorughout. They are VERY different on my stick.

So PEBOOT.BIN must be either a filecopy reference, or an extension?
Mine boots on the D800's, but I must've done this out-of-sequence and screwed it up in a way that it doesn't matter on the laptops, but BSODs on any other computer (I skinned the cat wrong).
I need to do like Bart says and clean the slate. I should "format g: /u", not just format. This is confusing to the point of no longer being educational because I don't know for certain when "what I did" caused "what I'm seeing".
I will have to take the D800 laptop home tonight if I'm going to continue this project sensibly.

hi i cannot find the fat bootsector entries !!!

i have used the tiny hexer
open the disc but the pic bart shows does not match with my picture !!!

the second pic with the byte shown for active partiton machted.

what do i wrong?

sorry my english is not the best

I put BartPE on a flash drive (AVB 512Mb) manually. It works fine!
I'd like to share my experience with the list.
1) I didn't use Bart's batch, though I used it as guidance. Also I didn't use additional boot sector image.
2) It's important to prepare your flash drive properly. I used following procedure:
a) format the drive with the utility that comes from vendor (or make it bootable, i.e. create MBR with another software).
b) run BootItNG and delete excessive (hidden) partitions if present.
c) from BootItNG format one big partition (Fat 6h).
d) format this partition again under NT from Disk Manager.
e) try to boot from the flash drive. It should result in message: "NTLDR not found"
If you don't get this message, your MBR is not OK for booting BartPE - keep trying with other software until you get "NTLDR not found". Also, play with BIOS boot settings (I used "USB-HDD").
3) Copy to the root of your flash drive from BartPE output directory:
a) winbom.ini
b) \i386\setupldr.bin as ntldr
c) \i386\ntdetect.com
d) all directories
4) Rename i386 to minint
Done! Try to boot from it .
Notes:
I did my preparations under W2K, it should be the same with XP.
BootItNG - free download from http://www.bootitng.com/utilities.html
Reformatting under NT is necessary to set MBR to what NT considers right for that drive (as I understand, NT rewrites MBR with its own when formats bootable drive). On preparation PC you may need to replace vendor's driver that supports your flash (if any) with generic MS's.
I have a question! Does anybody know how NT determines that particular device is removable drive and how to change it? That would allow to install NT on a flash!
BTW, there is a very interesting freeware that removes XP/W2K/2003 components before(!) setup: http://nuhi.msfn.org/nlite.html

@alexei

Nice news.
However, from the experience of people that have had sucess with this before, it seems that there are some hardware and bios issues involved. So, is it easy to check if your flash drive boots OK on some other machines? Would be interesting to know.

regards

Okay now after removing all drives in a system sitting around, I booted PE (with flash drive in only) and copied the files (not installed, just copied), reboot and - it works! Tried on my main machine, got stop 7B now I am more puzzled...


npropanol

whitch tool do you use to format and make a USB flash drive (stick) bootable?

@FeelGood
We've used several utilities:
- one built into Bart's utility mentioned at first post on this thread (menu choice)
- manufacturer USB stick boot utilities (they all format for booting DOS)
- or format in any non-bootable way and use hex-editor to manually set the drive bootable

The views in Tiny Hexer can be made to look different depending on the setting you choose. Go to "Options" and then "Editor settings". In Bart's first picture, the row size is set to "8" and the column size to "1". In the last, BIG picture, the row size is set to 16 (the default).

My problem is Tiny Hexer is apparently read-only. When I want to save, I don't see any choice anywhere to write-to-disk. I can write a copy of the sector to a useless file, but not to the original. The "Save" option remains grayed-out. Also, going to "File", "Process", "Write Process Memory" is grayed-out.
Under "View", the "No editing" option is off.
Because of this, I've been using Tiny Hexer only as reference.
What am I doing wrong? Do I have wrong version of Tiny Hexer (1.0.1.30, June 26, 2004)?

If I have to write, I've been using DiskProbe, which is a clunker of an interface.

JeffO, there is another download for Tiny Hexer on their site that says for Bart Pe. It is called small edition or something. It allows write to disk. Sean

http://www.mirkes.de/en/freeware/tinyhex/s...malledition.php

Not sure how critical this is...
I ran some tests and analyzed the differences.

Using the same stick, I formatted using the HP utility and took snapshots of the bootsector and MBR.
Then I used Windows Explorer to do a regular format.
The Dell boot utility refused to run on my Kingston stick.
Then I used Bart's format command, which uses Windows FORMAT command but with parameters (format f: /fs:fat /v:BartPE /backup /force).

The Windows command, no matter how you switch it, creates an MBR where the "partition type" is "06" at the 1C2h location. But the HP utility uses "0E", which is 16-bit FAT LBA.

I believe this must be significant. Regardless of whether you use the HP utility to format regular or format bootable, the partition type will be made "0E".

Does this differs from all other utilities that don't work?

I could never get mine to boot (not at all) until I finally formatted as FAT16!

npropanol

I finally got swift and printed out the bootsectors and the MBRs of each Windows format and HP format, then I over-lapped them and held them up to the window. With thin enough paper, you can compare both entire fields quickly.

The bootsectors of the Windows and HP formats had only 5 differences:
Locations 024-02A: HP=80 00 29 3C AC 48 68, Win=00 00 29 E9 3B 52 00

Slight change of subject:
A website I went to explained that there is a "physical bootsector" and also might be an "OS bootsector". This would explain the confusion over the bootsector at my "\\.\F:" differing from my peboot.bin. The bin file, if present, is the OS bootsector.
The physical bootsector is indeed hidden on the first sector un-useable for any other purpose (0-0).
The MBR is on the first useable sector (0-1).

I hope I have this right?

I'm still foggy on how the two relate to each other and what differences are allowed, needed, or bogus.
I've just completed all the steps in the BartPE/USB build.
comparing peboot.bin to my "physical bootsector", there's only one difference:
The physical points to NTLDR.
Peboot.bin points to PELDR.
Both are present, but I still BSOD 7B.
If I edit the physical bootsector to point to PELDR, the Dim2400 still 7B's.

In order to boot from USB:
- the BIOS/mobo chipset has to allow it,
- the USB stick firmware has to allow it (and many manufacturers are suddenly releasing firmware updates)
- and your phys. bootsector/MBR/OS bootsector must allow it.

The way assembly code works is fairly robust. It goes through a list of possibilities for each action. "If this, then do this, but if this, do that."
My Latitude D800 boots with ease; the Dimension 2400 doesn't. I haven't given up hope on the 2400 because I hope either a new BIOS will come out, or there might be a firmware update for my Kingston stick, or I might figure out some hex code in the bootsector or MBR that make it bootable on all USB-bootable systems.

@scAn
I hadn't realized that the small Tiny Hexer had the added feature. For the most-part, it seemed to be a stripped-down version of Tiny Hexer. It does the trick well. Thanks for the tip.

This worked just dandy for me using a Lexar JumpDrive (256mb) and an IBM T41p, with what I'm pretty sure is the latest BIOS. I didn't even need to change the 0001 to 8001. I'll be trying it out on other keys, but our office only has IBMs so I can't give you much info on other systems.

That's exactly how I did it, and now it finally works! I didn't have to edit the boot sector at all.

I have an Apacer ST202 256MB and IBM T40 (newest BIOS 3.02)

Edit:

It also works on an IBM T41 BIOS 3.05a (1RETC6WW) dated 14.5.2004

Last night I visited Intel and downloaded the EFI programming documentation. It's well over 1000 pages, plus another update document full of corrections.
USB can possibly boot under Legacy standards by following certain old-fashioned methods, but that's extremely problematic.

The new EFI standards seem to be towards allowing any USB device to boot, regardless of how the drive is set up. They want you to have to do only two things:
1) turn the boot-to-USB choice on in BIOS
2) have an OS on the USB device
The EFI standard isn't supposed to care what the USB device is, USB CDROM, USB stick, USB drive, Flashcard memory,...

The BIOS is key to how much trouble you'll have. How closely and how well it adheres to the new standards will make ALL the difference.

The confusing thing is, I did read a section that stated it should be possible to boot any Legacy BIOS to USB if "Legacy USB" support is turned on in the BIOS. (The new EFI standard doesn't require it.) Nothing I've seen in real life supports this. But it does give me hope that where there's a will, there's a way.

If you bought your computer this year, and it's an Intel, IBM, or Compaq motherboard, it will likely boot to USB without much trouble.

Ok.. so I used the HP utility to format/partition without the dos boot option. I then ran the peinst.bat and finally (after many many many tries) the usb stick will start booting to pe.

I had to move txtsetup.sif from minint to minint/system32 for some reason. But now I am getting:

"File \$WIN_NT$.~BT\system32\biosinfo.inf could not be loaded."
"Error code 18"

It forces me to reboot.

I've looked at the file and I can't figure out anything wrong with it. I've also tried placing the file in minint/system32 as well as the root of the drive. Neither helped.

I'm trying to boot this on a Dell Optiplex GX270 and am using a 128MB memorex thumbdrive. If I can get this step working I will be so happy.

I'm getting the same thing when I use the HP utilities on a 256MB Lexar USB stick.

When I tried partitioning - then formatting - the drive as an NTFS volume through XP's Disk Manager, I don't get the "...BIOSINFO.INF..." fault; rather, the system immediately reboots itself after the BartPE 'Setup is inspecting...' line is displayed.

Odd, to say the least.

Boot to STOP 7B after splash screen with a USB harddisk on a Dell GX270, so the boot sector is OK, only the BIOS dont't support this kind of usb devices, am I correct ?

Correct... and,er, maybe not.
A fully modern BIOS seems to boot with just the HP format and a copy of the PE files.
A fully NON-supporting BIOS won't boot.
A partially supportive BIOS will probably require the usual hex values in the proper places that Bart illustrated at the beginning of this thread for making a device bootable.

Your GX270 would have to be no more than about 9 or 10 months old (Nov. '03) to have the correct chipset. Also, your BIOS must not be older than about December 2003.
I also think that there are some physical limitations in some chipsets that mean an older computer will never be able to boot to USB even with a BIOS upgrade.

The difference between abovementioned HP and Windows XP SP1 utility formated drives is in third (0x20) if viewed in tinehex line.
It must be (as formated by HP utility)
C17F 0F00 8000 2919 546A DC4E 4F20 4E41
And actually it is already active (you can check/set it in right-ckicking on My computer->Manage/Disk Management.
If someone needs, I can upload hex file, but I have no anonymous accesible location now.

It worked with Apacer HT203 disk I bought today (24 MByte/sec read speed!)