Flash audio won't play on friend's pc

[Peegee]

If this were just one browser I'd think it was the adblock issue (weird since it doesn't happen on FF3), but it affects every browser - Chrome, FF, IE7...

It's the 'flash audio doesn't play' issue, or rather that flash audio is very low.

I have reinstalled flash player several times, rebooted, with no difference. Tried some registry fixes - same.

Since it affects every browser I think it's a flash issue but not sure what else to try.

edit: windows xp