I've seen this error posted a few times. The solutions i've seen have been in relation to sound card drivers and motherboard drivers. You might check and make sure those drivers are XP compatible as it usually turns out to be a hardware compatibility issue. Good luck.
I had this issue for a long time with the XP bettas on an MSI Motherboard - Try getting the lattest Bios (me very carefull up-dating your bios) and latest drivers for your Chipset - Via have had a few up-dates for XP and I'm sure the others will follow.
Make sure all your PCI slots are set to PnP and your bios is set to "PnP Enabled OS"
The IRQ settings are a thing of the past - The bios gives total control to the OS and using ACPI - you might see allot of IRQ's being used by the same device - don't worry about it - you can't change IRQ's anyway and this is normal.
EP, glad to see you come back and tidy up...did want to ask a one day favor, I want to enhance my resume , was hoping you could make me administrator for a day, if so, take me right off since I won't be here to do anything, and don't know the slightest about the board, but it would be nice putting "served administrator osnn", if can do, THANKS