No sound...???

Hi, all.

This started a little bit after a fiasco with some malware (MS Removal Tool). I finally fixed the problem with the virus, and everything was running normally until I started my computer one day, went to YouTube, and played a video. No sound. I checked my speakers, YouTube itself, and went into my volume control panel and double checked everything.
Everything was fine. So I went to play music in Windows Media Player, and I get a message saying "You need an audio codec to play this file"
I tried playing Medal of Honor: Allied Assault (Old, I know.), and there was sound. I tried a few other games, same thing, there's sound.
I went to a couple of forums, one never replied, and the other ended on the note of them not knowing what to do.

Everything plays sound except for WMP, IE or Firefox, any of the Windows Sounds, and Steam and Xfire have no sounds (Log on/log off, ect).
I've tried Microsoft Sam, I've tried the test in DXDIAG, those all work.
The guys at GeeksToGo told me to try VLC Audio Player for WMP-related sound files (MP3s, ect), and it works fine.
I'm really pulling my hair out here, I have no idea what to do. :banghead
I've updated my sound drivers, to no avail. I've also uninstalled SigmaTel Audio High Definition CODEC, and when I restarted it was replaced with IDT Audio1.

http://support.gateway.com/s/PC/R/1008880/1008880sp3.shtml
There's the specs, if that'll help.
I'm starting to wonder if I should reformat, but that's really the last thing I want to do.
I'm willing to retry anything if you think it'll fix the problem.

Please, any help would be SO greatly appreciated.
If you need any more info, I'll happily provide it.
Please, help me get my sound back! :cry:crybaby