"No Audio Device" Help!

A few days ago my sound suddenly stopped working without reason. I went to control panel > sound and audio devices and it tells me "no audio device" under the volume tab. Obviously I have a audio device because it was just working. The card (SBlaster Live! 5.1) works and has the proper drivers. The funny thiing is, I get sound playing World Of Warcraft, but I get no sound in any other application. I couldn't figure out what the hell is wrong so I tired taking the card out and moving it too another PCI slot and re-installing the drivers and it still was giving me the same problem. After that I was thinking maybe was something wrong with the soundcard so I went out last night and bought a new Sound Blaster X-FI Xtreme Gamer card. I went to install that thinking my problem would be solved but it's still doing the same thing. I really need help with this, with no sound my computer is basically useless


PC Specs:

Antec nine-hundred
BFG Tech GS-650 power supply
AMD 3500+
Asus A8V Deluxe
Corsair XMS matched pair 1GB
BFG Tech 6800 GT OC
Western Digital Caviar 80gig
Hitachi DVD-ROM GD-5000
Logitech G15 keyboard
Microsoft IntelliMouse Explorer 2.0
Samsung SyncMaster 793mb
Sound Blaster X-FI Xtreme Gamer

I have the same exact issue as you, and I'm fortunate to come across this thread. My sound does nothing in YouTube, WMP, etc. But the weird thing is, I can play Zombie Panic: Source and Team Fortress 2 with sound. I can't select my default audio device because the options are grayed out and the box is replaced with Moden #1 Line Playback.