Soundcards are notorious for IRQ conflics. In the DeviceManager, pick ViewByResources and open up the IRQ listing. See what IRQ the soundcard is using and see if there's any others using it.
Most likely, you may have a non-plug&pray sound-card that uses hard-wired jumpers to pick IRQs. To make it work:
1. turn off machine and pull out the soundcard and see if there are jumpers to pick the IRQ. Most common settings are IRQ 5 or 9, I prefer 5.
2. boot-up machine and get into the BIOS (hit F1 or Del or whatever keys needed on boot).
3. go to menu like PCI/IRQ/Plug & Play settings. There should be a list of available IRQs with settings like Auto/Reserved/ISA, and pick Reserved or ISA for IRQ-5 depending upon the motherboard BIOS. This makes Windows not try to use that IRQ for any other device.
4. reboot and see if driver works this time. Might need to uninstall device driver, reboot, let it re-detect and re-install driver with proper IRQ selected. You might even need to open up DeviceManager afterwards and go into Driver and manually set the IRQ to the same one you set on the jumper on the soundcard.
P.S. I've seen driver .INF files cause confusion for Windows. Some manufacturers puts ALL of the files into one directory and Windows doesn't correctly parse them properly (Win9x drivers are set up differently than WinNT/2K/XP). If this is the case, rename the Win9x .INF files to something like .W9x so that Windows2K/XP only looks at the correct ones (open up .INF files in WordPad and read first couple of comment lines). Otherwise, if your driver disk is nicely divided into Win9x, Win2K, WinXP, SCO, LINUX, etc. folders, make sure you point the DeviceInstaller to the correct folder when it detects teh card.
What a mess... get a Mac!
