Solved the problem of playing webpage videos without sound in Windows 7.

The local player has sound when listening to songs and watching movies, but it has no sound when playing FLASH on Tudou, Youku, Sina and other websites, as well as RMVB and WMV videos in online movies, and the music on the webpage cannot be heard either. You can play videos, music, and FLASH animations on your hard disk to hear the sound. It can be determined that this has nothing to do with the driver. Reinstalling the driver does not help.
In fact, this problem is also very common in Windows XP/Vista and has nothing to do with Windows 7. It is generally caused by the use of optimization software or the installation and uninstallation of various decoders.
To solve this problem, click "start" menu> "run" and enter "regedit" and press enter to open the Registry Editor, in the left-side pane, click "HKEY_LOCAL_MACHINE \ SOFTWARE \ Microsoft \ Windows NT \ CurrentVersion \ Drivers32", and then check whether there is a "wavemapper" value in the right pane. If no value exists, right-click the mouse icon in the blank area on the right, create a string value named "wavemapper", and double-click the value to set its "value data" to "msacm32.drv ", restart the computer to solve the problem.