Actually it seems like it does support USB booting:
http://www.google.com/search?hl=en&q=Compa...ble+key&spell=1(you might need to update your BIOS)
If it does, how it should, you can try installing XP normally, but you could have the 0x000007 STOP error if the USB bus is reset by XP while loading.
You can try ( no warranty implied) this method:
1) make a floppy this way
http://support.microsoft.com/default.aspx?...;305595&sd=tech2) Make your boot.ini as follows:
CODE
[Boot Loader]
Timeout=30
Default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[Operating Systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="XP 0/1"
multi(0)disk(0)rdisk(1)partition(1)\WINDOWS="XP 1/1"
multi(0)disk(0)rdisk(2)partition(1)\WINDOWS="XP 2/1"
I am assuming that XP is installed on the HD in the first partition and in a directory called WINDOWS.
3) Make a CD with a bootable image of the floppy
If the BIOS maps the USB KEY, you "might" be able to boot, but you could have the 0x000007 STOP error as well.
See this thread for some info on the problem:
http://www.911cd.net/forums/index.php?showtopic=10806jaclaz