Sound Disappeared

During the course of my trying to track down some malware, my sound suddenly disappeared. I suspect it's something I did, but I don't know what.

I tried earphones, to test whether it might be the speakers. The earphones won't work either.

I'm running Windows XP Pro. I checked services.msc, as suggested in another thread, and it says Windows Audio Service is started.

When I go to Control Panel, Sounds and Audio Devices, the Volume tab says "No Audio Device." Under the Hardware tab, the two entries with "audio" in the name are Legacy Audio Drivers and Hardware Audio Codecs. The notation, "This device is working properly" appears on both.

I'll appreciate any help I can get. Thanks.