Sound Problem: ME

I have a sound problem. I listened to MSN audio-video news in the morning, then turned off the machine, dismantled it and moved to another place. Now, I have video but no sound. Every hardware test shows the device is working properly. Any suggestion about what could have happened and/or how to get the sound back is welcome. Here are the detail of my rescue attempt.

First I checked System Device Manager. Nothing appears irregular. All properties read “this device is working properly”

Second: from Control Panel ---> Sound and Multimedia:

- Tab Sound:
Select a sound and click arrow to play. It does play but no sound comes out from the speakers.

- Tab Audio:
. preferred device correct
. volume is OK
. Advanced: speakers OK, performance OK

- Tab Voice:
. voice playback OK
. advanced OK
. voice test: microphone and playback both are OK.
. I pressed the OK button and got the following message saying that the sound hardware is working properly.

- Tab Device:
. nothing seems suspicious

That was the last tab. I clicked OK button and got the following message:

“Rundll32 has caused error in USER.EXE. Rundll32 will close now. If you continue to experience problems try restart your computer.” Indeed, I had to shut the computer down and reboot it.

I tested the speakers on my radio. They are OK.

.

Here is a fix for the error you are getting.
http://support.microsoft.com/default.aspx?kbid=307908