see if you can find out exactly the file name that appears
DRIVER_IRQL_NOT_LESS_OR_EQUAL
The system attempted to access pageable memory using a kernel process IRQL that was too high. The most typical cause is a bad device driver (one that uses improper addresses). It can also be caused by caused by faulty or mismatched RAM, or a damaged pagefile.
With that mentioned, it might be that you have a driver that has gone 'bad' - reinstalling the driver may resolve this issue
Can you get into XP at all?
If you can:
-Right click on My Computer on the desktop and choose properties
-Go to the hardware tab
-Click on Device Manager
Look down the list and look for anything that has Yellow Marks next to them and post them here