Please help me fix weird audio problem with my PC

The audio works on everything except when I play youtube or other videos.
I upgraded adobe flash, that didn't change anything.
I know the problem is in my desktop PC because when I connect the sound system to my laptop it works normally and I have sound with youtubes.

Any suggestions for what I might try to fix this?

Problem fixed.

I've been waiting since I got back from Mobile to be able to HEAR this video, Eric.
Jimmy Hall and Wet Willie 40 effing years ago.
This is going on my jukebox TODAY.

I enjoyed Wet Willie at Bayfest... it was captivating to say the least.

Did you get the audio fixed yet, Bob?