According to Windows my Realtek AC97 is fine but I get no sound. It's not disabled in services and on volume control it's set to highest. I think it was webHancer which hacked in last night
before putting back your backup data (and I really mean that) finish the installation with windows updates, drivers, antivir software and all the nice stuff. And than scan your backup before putting it back...
(ps: that needs prolly a big usb stick or a spare hdd)
I swear sometimes you're just completely unhelpful. Every problem he has you put down to how many anti-virus packages he has installed, or what he "must have" done to his PC. If you can't offer a realistic, helpful solution, why bother? As it turns out, it was a very simple problem, that was nothing to do with how his computer is maintained.