have you tried disabling com ports and lpt port to see if it frees up an irq?

All disabled except mouse IRQ12.
Plus I've tried resource reservation, no change.

Did you try to set the irq in the bios and set pnp able os to no.?

No such option.

can you disable irq for vga in bios?

Have you tried disabling IRQ Steering in Windows? Might be worth a shot...

http://support.microsoft.com/kb/182628

You might have to play around with that. On a sidenote, I've had both SW1000XG and DSP2416 cards installed alongside 5 other cards on a Win98SE rig, without issues.

Make sure control of hardware resource allocation is done in the BIOS and not by Windows. Set PnP OS to "No" in the BIOS setup if its available. Also if the option is present to assign a specific IRQ to a PCI slot, use it.

I managed to fix it by disabling ATi RAGE in the device manager.

@ NJRoadfan I can not make sure because BIOS has no such control switch.
@ Robertmo No, only DAC snooping.
@ Jaws This is a DeLL 😀

Quick follow up after trying at this again a few days back:

When installing SW1000XG into this PC and upon restarting, when it loads its drivers and configuration, the card emits a very loud buzzing noise and does not function. It is using the same IRQ as integrated Rage PRO graphics chip and IRQ Holder For PCI Steering (IRQ 9) as well as using an Memory Address FAFC0000-FAFFFFFF which is also a part of DEC21152 PCI to PCI Bridge whos range is FA000000-FBFFFFFF. Due to this memory conflict system would some times freeze up for a second or two when accessing folders and copying data.
Changing the IRQ causes an error message upon loading windows and explorer does not start. Changing the memory address causes an VSWXGDSP timeout and windows becomes frozen.

Tried everything in BIOS from disabling DAC Snooping, to disabling every possible device and changing various settings like ACPI to ON or OFF (IRQ9/10). I have tried every possible driver I have (2.0, 2.4, 3.4) and still it did not work.

But there is one and only thing I did not try, and that is placing the card into the FIRST PCI slot 😵
Once I did that the card works flawlessly (IRQ10 , FF000000-FF03FFFF). 😅 Hope this helps some one who is as stubborn about swapping PCI slots as me.