I have been having lock ups with my agp card (leadtek winfast geforce 2 GTS) and have come the conclusion that this may be a conflict with the agp alot sharing an irq with a pci card. Unforunately windows 98 wont allow me to change the irq through device manager. I have looked through my bios (MSI 6163) and have found only a way to dictate whether an irq will take legacy isa or a pci/isa pnp card. If someone could please help me out I would be much in your debt
Try moving the PCI card to another slot. motherboards are wired so that a small number of hardware interrupt lines are sent from particular slots, often times this means that certain slots will always share. For example on the Asus A7V133 there are 4 hardware interrupts (A-D), with A being shared by the AGP and PCI slot 1, B being send to the AGP and slot 2, C being for slot 3, and D being for slots 4 and 5. Generally the BIOS and then the OS will share a software interrupt between devices on the same hardware interrupt, if that makes sense. After moving the card, from the BIOS, also do "clear configuration on next boot" to erase any resource assignments the BIOS may be hanging onto for the card. BIOSs have a memory of cards that have been in the system and sometimes keep reserving resources even for empty slots because they're too stupid to realize that a card you removed won't be coming back, or has shifted to another slot. Try turning off "plug and play OS" to see if this gives you back the ability to set the resources under Win98. Disable an unused COM port (like COM2) to free up a spare (software) IRQ.