No sound on AMILO laptop

Question

....hi there, a friend 'cleaned' my laptop and thought he was being helpful by putting xp professional on it. Anyway, after months of getting a little pop up window telling me that the copy of windows was not authentic, I tried to find the original disks it came with - couldn't. So I bought a new copy of windows xp. I put it on (Fujitsu siemens AMILO-EL) and now I have no sound??Any ideas - ??