Vista sound help.

[scotland1]

Well I recently installed windows vista home premium, everything was fine, my comp's compatible, everything. Untill I started up GMod, Nox CTF server. It sounded like constant feedback from a mic, everything was crackley, I couldnt hear anything. I retried the server, nothing, tried sandbox, nothing. Yesterday in single player it was fine. I don't know what the problem is.

Does anyone else have vista that knows how to stop this?

UPDATE: I just joined the CTF server again, and after 5 seconds my screen looks like this:
pic1
pic2

What the ****?

UPDATE 2: I just played bioshock, same thing. Crackley, can't hear a thing. I'm getting really pissed off now.

Update 3: I just installed a new soundcard driver, the wrong one. I rolled back to my previous driver, which was one I didn't even know existed. My sound card is SigmaTel high definition audio CODEC. I've looked for a driver that will work with vista, but can't find one.
Help me please!

 

[Asus]

What brand is your PC? Model?
Sigmatel doesn't support end-user products. Have to go through the company who bundled the sound chip with your PC.

About the video thing. Could your PC be over heating?
Otherwise there might be an issue that is beyond just audio drivers. Maybe something to do with DirectX (video/audio).

 

[scotland1]

My PC is a dell dimension 9200 with an nvidia geforce 8600 graphics card. I don't think it's overheating. It hasn't been on for a while. I have DX 10. Everything was fine before I installed vista. My comp is compatible. I havent changed anything but the graphics card which supports vista.

 

[scotland1]

I REALLY need to get this fixed. I can't hear anything. there's no point in having a computer if I can't hear anything.

 

[scotland1]

****ING YES! I downloaded this maintainence thing and it worked! Thanks anyway.