I brought a PCI USB card because my brand new Gigabyte P965 DS3 only comes with 2 onboard USB 2.0 slots. However when I install this card I find my sound card (Creative X-Fi Xtreame Music) no longer works however when I take it out my sound works fine again.
Is this an IRQ conflict? Or could it be something else? If so how do I fix it?
So far I've tried using different PCI slots (I only have 3 anyway), and I’ve flashed the mobo to the latest Bios (F6)
I would return the card (or keep as a spare) and try to use the on-board USB headers first. There are three I can see:
Look at the yellow connectors at the extreme left (mid-board next to the pci slots at the edge), they should support up to six more ports with your case or a usb extender panel like this or similar. I have one with memory card slots as well is really convenient.
Yeah I see them, troble is my board didn't come with any extras like that. Shame, it's not a big deal the card only cost 8 quid so I'm not loosing out on loads of money but it would nice to try and fix it.
I thougth Windows XP had sorted out IRQ conflicts anyway?
Your sound card stops working when you install the USB card because of an IRQ conflict. Creative requires IRQ 5 to be available. Your USB card is also using IRQ 5 and it gets assigned to the USB card first during boot-up. Now the sound card won't work. Changing slots won't make any difference.
What you ned to do is go into your BIOS setup, in tne section related to peripherals / PCI. Find the part that allows you to manually reserve IRQs and reserve IRQ 5. Save the new settings and reboot. You shoud be good to go.
As for your comment about Windows "sorting out" IRQ conflicts, you must be joking. Windows does "sort" IRQs, but in a very strange manner. More critically, when the BIOS is allowed to assign IRQs automatically, Windows will frequently override the hardware auto assignments with its own rules. This can lead to some very strange and difficult to resolve conflicts and operational failures.