There are unnecessary processes being started that are causing the problem. Have Windows XP sort them out by following these directions:
1. Go to Start>Run> type MSCONFIG.
2. When the box appears, click on the STARTUP tab.
3. Select DISABLE ALL, then hit APPLY then hit OKAY.
4. Reboot and get rid the MSCONFIG splash screen when it appears upon reboot.
5. If you are prompted to reboot again, do so.
You will no longer be bothered by the IRQL_NOT_LESS_OR_EQUAL blue screen. The processes that you DO need were automatically re-enabled when you did the reboot. You should be in good shape now.