Why would sound suddenly stop working on Windows 7?

Solution 1:

Don't know much about any issues particular with Windows 7, but you can test if it's a hardware problem rather easily by booting up into an alternate OS installation. Assuming you don't have a dual-boot system, this can also be accomplished with a linux live CD that supports your laptop.

I personally use Knoppix for such things (mostly just because I happen to have the CD handy) but there's myriad other options available. If sound works on one operating system, but not under the other, then it's pretty much a software problem. If sound doesn't work with either, it's probably a hardware failure.

Solution 2:

I've had this to. I get a bit of static then nothing. Itunes won't even play a song.

To fix it tho you can go to the sound settings in the control pannel, go properties on your sounds device and under I think the advanced tab there is a test button. In the drop down list choose something different to what it is on, it will ask are you sure, say yes and the sound will work again.