Heres my problem, I have a computer (600mhz, 256ram, Amd motherboard & CPU, gateway bios) that runs and boots up fine with NO cmos errors etc.. but when I install anything extra in my pci slots the computer will lockup soon after windows starts. At the moment I only have one pci slot in use by my sound card and the agp slot for video. Under Device Manager it states the SCI IRQ USED BY acpi BUS has a code 11 error. What can I do to fix this? Bios list nothing of ACPI. Is there a software solution???

Well, I need to update my problem, I reinstalled the amd drivers and got rid of the code 11 error but the PCI issue is there, not only does the computer lock up after windows starts up but it sometimes reboots rather than lockup.. man I need help with this

Are you by chance using the first PCI slot below the AGP slot for the sound? On some older MBoards the chipset didn't do a great job of managing the system resources. I suggest that you look at the manual for your MBoard. There may be a listing there to show what PCI slots default to what IRQ. Many times the first slot below the AGP shared an IRQ with the AGP. There are a couple of things you can do. There may be a listing in your BIOS to assign an IRQ for AGP. If so, enable. Then use PCI slots with default IRQs that don't conflict with things you can't change. Also there may be a couple of settings in the BIOS concerning how the resources are assigned. They can be assigned by the MBoard chipset or by the OS. You need to look for settings like PnP aware OS. The proper setting here is a crap shoot. Sometimes it is good to enable, sometimes not. There may also be a setting to reset configuration data. If there is, try enabling this for one boot cycle. One other thing. Look at the MB for bulging or leaking capacitors.

As for which pci slot I use, the only one that works is the third pci slot from the agp, all others cause windows shut down. Thanks for all the extra info, I've been trying every setting but honestly this gateway bios is very limited in options