Sound driver keeps uninstalling??

[kasdaye]

I have a Packard Bell computer with a SiS 7012 audio driver. My sound was working perfectly up until about a month ago when it mysteriously uninstalled. I checked device manager and there was no conflict and when I checked Sound Devices in the control panel, there was no audio device installed.

I manually reinstalled my sound driver and it seemed to work but on reboot the sound was gone again. I loaded in safe mode, uninstalled all sound drivers and let my system detect them. This worked for a while and then my sound would be gone. Sometimes it would let me manually install the drivers, sometimes this caused a device conflict I couldn't seem to resolve.

So I reformatted my hard drive and reinstalled everything thinking that maybe it was a software conflict that I wasn't clever enough to figure out. And everything was working fine up until today. I had no sound again but a system restore to a time when sound was working seems to sort everything out.

I'm at a loss as to what to do next time this happens. I won't always be able to system restore. Especially if I've removed a virus after running a check. And I can't tell what I am doing to remove my drivers. Does it mean my sound card/audio chip is faulty? Today before things went wrong I had been using a plug and play device. Can these sometimes cause these issues?

Any help would be much appreciated. I am thinking of buying a PCI slot sound card to replace my onboard one.

Board: NEC COMPUTERS INTERNATIONAL SiS650 1.0
Windows XP Professional Service Pack 2 (build 2600)
MPU-401 Compatible MIDI Device
SiS 7012 Audio Driver
Standard Game Port
Unimodem Half-Duplex Audio Device