No sound from video clip played in Media Player 11 on Vista

Before upgrading to Window Vista, I was able to play music in my library and from the web as well in the Windows Media Player 11. But after the upgrade, I am not able to heard sound if I play any video clip from some online website. The operating system as well as the media player both were upgraded at the same time, so i cant say for sure which might be having issues?

Any ideas?

Have you tried uninstalling and reinstalling the sound card drivers in your computer? What is your computer specifications anyways? You might also need to install some codec software in your pc, which is required to play different file formats of video. To update the sound card driver, follow these steps:

1. Click Start, click Control Panel, and then double-click System.
2. Click the Hardware tab, and then click Device Manager.
3. If you are prompted for an administrator password or for confirmation, type the password, or click Continue.
4. Click Sound, video, and game controllers to expand.
5. Under Sound, video, and game controllers, double-click the entry for your sound card, and then click the Driver tab.
6. If a Driver tab is not present, the entry that you clicked under Sound, video, and game controllers may not be the correct entry for your sound card. Try clicking any additional entries listed under Sound, video, and game controllers.
7. Click Update Driver Software.
8. Follow the Update Driver Software Wizard to update the sound card driver.

I appreciate your reply, thank you very much, I will go and try to look at the sound driver and see if that works. But yes, I do get the start up sound when I start my machine which is running on Windows Vista.

Even, I was facing similar kind of issues after installing Windows Media Player 11. But I found a solution for it and that was, if I enabled the Windows Live Messenger plugin in the Tools Menu, then I was able to get the sound. Hope that this will help you out.