In the past I had come across this problem and was able to resolve with combo fix and malwarebytes but this time it wasn't able to fix it. Tried Search and Destroy along with AVG finally ran Norton's online scan and it seemed to have resolved the issue. So I thought.
Today I noticed no sound again but this time when I checked the volume indicator it says I have no active mixer devices available. I checked the hardware manager and I see no issues with my sound device. Seems like something has disabled my sound without disabling the sound card. I rebooted to see if that would fix it. The volume indicator would work properly for a short period of time after reboot but soon enough it would say no mixer devices available. Also received a popup shortly after opening firefox...something that wasn't happening before.
I am sure that I have some type of wares but unsure at this time on how to remove it as nothing seems to be able to find anything.
Running XP Home Edition
I think I should have posted this in the "Am I infected? What do I do" section of the forum.
Edited by Budapest, 02 February 2011 - 10:44 PM.
Moved from XP ~BP