No output device detected after installing Windows 7

Hello,

After installing Windows 7, I got the message near de loudspeaker icon "no output device detected" and a red cross.
When I go to control panel, sounds, I do not see anything written when I click the play-back button.

My PC is a Packard Bell Imedia.

The sound worked well until I installed Avast antivirus and Windows updates.

Please help !

Thank you

Hello,

No one can help ?

spazgadget said:

Hello there!
It appears to me that you need to install or update your sound driver.

-spaz

I already tried and it does not work !

Pauly said:

Have you check device manager for any caution marks against sound, are there entries for sound

There are no caution marks against sound. It says that I have installed all drivers for Asustek Device Capture.