Multimedia Audio Controller (Code 28)

Hi i have a problem with a packard bell computer i reinstalled windows xp pro for my uncle now there is no sound when i went into Device Manager there is (!) by Multimedia Audio Controller when i click properties its saying (Code 28) all i have is the info on tower as follows Intel Inside Celeron D, IMEDIA 1404, S/N:043060920422 I have been on http://support.packardbell.com/uk/ and type in the S/N and the tower is not the same as mine it is diffrent i tryed the sound driver they recomended me (SigmaTel C-Major (STAC97N) for SiS audio driver) Didnt fix the problem..? Please can anyone help its so stressing me out

Thanks in Advance