There are some issues installing win2k sp4 from bartpe,
1. The system does not reboot after the files are copied.
you will need to use some sort of unattend.cmd, which sets the permissions on the install drive, and effects the reboot. I build this by a script file at runtime.
echo xcacls d:
xcacls.exe d:\ /P Everyone:F /Y
echo winnt50 setup
g:\wnt50sp4\i386\winnt32.exe /s:g:\wnt50sp4\i386 /tempdrive:d: /unattend:S:\unattend.txt /noreboot
: code to reboot bartpe
This will install Windows onto the D: drive, using source from g:\wnt50sp4.
The batch generates an error soon after it starts (ie winnt32 sends strange messages). So you have to attend it that far.
If you plan to dual-boot win2k and bartpe, then you need further magick, such as to restore the bartpe NTLDR and NTDETECT.COM to the c:\ drive. You can use $OEM$\$C\ structure to do this. You can use the same $OEM$ structure, to replace the sysoc.inf with the hacked version, and also to put in your own oem bitmap and info file.
I have installed win2k from bartpe many times. The SP2 build does not work, but you can use SP1.