Having the Same issue on Inspiron 6000 with ATI gpu.
Stop 0xB4. Will not boot into safe mode. Will not get past a certain point loading from a windows disk (setup/repair), same message for every attempt. The message comes up while loading system files. It seems that the video drivers or IRQs may be corrupt/conflicting. The bios does not allow for IRQ setting changes. I read that adjusting the amount of virtual memory on the pagefile will fix this message as well, but since I can't load the OS I have no way to determine.
The only reference I could find regarding this error and windows XP was at
http://www.pcsupportsource.com/xp_stop_messages.htm . Unfortunately it doesn't give much information except to try booting into safemode which is not possible. I did, however ,find an IRQ setting change on the MSDN website for this stop code in Win2k, but again... not being able to access the IRQ settings in the bios is kinda hurting my progress. Any suggestions?