Random Loss of sound driver HELP PLZZ

I have encountered a rather funny issue.... I have a completely random loss of sound driver and i reinstall it and it goes and randomly disappears. no sound installed..... i am running win xp media center.
I have found no pattern What so Ever,.....HELP me plz

Is it on-board sound or do you have a PCI sound card?

Have you tried turning System Restore off? Right click My Computer and choose Properties then look on the System Restore tab. Turn system restore off, then install your driver, then reboot, then turn system restore on again

Its an onboard card in a toshiba laptop.
I'll check the system restore. Im not sure what else to do...i left the comp on and i still lose the sound randomly

Strange...
Possible things to check:

1. Are your System standby/hibernation settings affecting the sound. I guess this is only an issue if the sound stays off even after a full reboot.
2. Do you you multiple sound output devices which may be conflicting?
Have you got any audio software installed which may have installed some invasive drivers?
3. Failing all of the above and if, as the Bishop suggested, a System restore does not work, it may be a hardware problem

I suggested system restore as its function is to repair the guts of Windows automatically and it sometimes steps in to undo changes. Since it's a driver you're having problems with, system restore has to be a suspect