No audio in Streaming Video

I have a problem that I can't quite figure out.

I went away for the summer for work, and while i was gone somebody was messing around with my computer.
When I got back i noticed i have no audio on any of my streaming videos on websites like google video, youtube or break.com
The wierd thing is I do get audio one or two smaller websites that don't host off of those 'big names'.
Anyhow I tried to solve the problem myself but have found no luck.
I tried virus scans, spyware, any kind of scanner they have listed on the net.
I reinstalled internet explorer, i tried using fire fox. No avail. All sound settings are set to high, and i double checked on both the browser and control panel (my music works perfectly). I reinstalled quick time and windows media player even followed some wanky instructions on the net to figure it out but to no avail.
The only solution I could think of is doing a system restore, but I've modified my computer so much and its been so long since the computers been running since the problem cropped up that I dont think it will work and I dont want to try to change it.

Anybody help?

Thanks

 

What about flash player? Did you uninstall that and reinstall that to. A lot of video sites use flash player.

 

oh yeah , sorry left that out too.

Yeah i uninstalled and reinstalled that too.

its ridiculous