Recht vanuit een forum met hetzelfde probleem :
Go to Start then Control Panel
Double click on the Sound Tool
Click on the Recording tab
Right click and select "View Disabled Devices"
Enable the Stereo Mix
also try this:
go to Control Panel and then Sound. Double click on Speakers and select the Advanced tab. Set your default format to 16 Bit, 44100 Hz (CD-Quality). this worked for quiet a few ppl.
Cod 4 Modern Warfare error :O - Tech Support Forum
Probeer eens of dat helpt.