PCI Sound Card Incompatible with Win XP Pro

My Elite MoBO has a complex multichannel audio output capability which is beyond my comprehension (or interest). I bought a PCI sound card to replace it and this works fine for my purposes–streaming radio, system sounds and the like.
However, it is a rickety thing–very often minor activity causes loss of access and a check in Sounds and Audio will show no audio device detected. I then uninstall the driver for the PCI card, shut down and reboot and the sound is back until the next problem (which has been as simple as changing the volume control on my speakers.)
I know the driver is older than XP Pro and there is no on-line driver available for this CMi8738/C3D device. I could buy a new, later-model card, but quickly get into trouble with incompatibility with XPPro because of the Gates backward-compatibility conundrum.
Any ideas how to circumvent the "you must "upgrade" imperative"?
