You may have to update some software and troubleshoot, try a few of these methods.
Method 1:
*You may update the latest flash player and check:
http://get.adobe.com/flashplayer/Method 2:
You may open Internet Explorer, preferably to a page that should be playing some sound.
a. Click on the volume icon in the windows system tray (in the right-hand lower corner of the taskbar), and then click on the link labeled "Mixer".
b. A panel will open showing the individual volume levels of all running apps that play sounds (you may need to scroll to the right to see all of them).
c. Make sure that the volume level belonging to Internet Explorer is adjusted properly.
Method 3:
*If the issue still persist you may perform clean boot, this issue might occur if any third party program causing the issue. Placing the computer in a clean boot state and troubleshoot the issue. You can start Windows Vista or Windows 7 by using a minimal set of drivers and startup programs. This kind of startup is known as a "clean boot." A clean boot helps eliminate software conflicts.
How to troubleshoot a problem by performing a clean boot in Windows Vista or in Windows 7
http://support.microsoft.com/kb/929135 if this doesn't work, update the latest plug ins and use a different browser.
This post was edited by Welterweight on May 19 2013 01:01am