My Flash Audio doesn't seem to be working.

Most video websites, such as YouTube, use Flash for their videos. A lot of people have problems with the Adobe Flash browser plugin. The most common problem is that the sound is not working. Below you can find 10 solutions for Flash related sound problems.

Flash stores its files in a temporary files folder. A corrupt download can cause the sound problems.
Delete the following folders:
C:\Documents and Settings\%UserName%\Application Data\Adobe\Flash Player
C:\Documents and Settings\%UserName%\Application Data\Macromedia\Flash Player

Empty your temporary internet files.
Internet Explorer: Tools -> Internet Options
Firefox: Tools -> Clear Private Data
Opera: Tools -> Delete Private Data

Empty your temporary files folder.
Use this command to empty your temporary files folder: Start -> Run -> RMDIR /S /Q "%TEMP%"

Install the latest version of the Flash plugin.
You can download it HERE. If you have problems upgrading the plugin, then uninstall your existing version first with this tool. Close your browser(s) before you run the uninstall tool.

Run the K-Lite Codec Tweak Tool.
You can download it HERE. Near the top you should see an option to fix the sound (Midi, WaveOut). Select that and press Next. If the option is greyed out, then that particular registry fix is not needed.

Go to the Flash Player Settings Manager website.
Enter site HERE. Check the box called "Allow third-party Flash content to store data on your computer."

Check if your sound device settings are correct:
Start -> Settings -> Control Panel -> Sound and Audio Devices -> Audio

If you have QuickTime installed, then go to the QuickTime control panel.
On the Audio tab, set "Default Music Synthesizer" to "General MIDI".
On the Advanced tab, disable "Enable playback of Adobe Flash tracks".
On the browser tab, click on "MIME Settings". Under "Miscellaneous", make sure "Flash media" is unchecked.

Check if the file msacm32.drv is present in your Windows system32 folder.
If not, copy it from another PC (that has the same version of Windows) and place the file in the system32 folder, or try running the System File Checker utility.

If you are also having sound problems with other applications, then re-installing your audio drivers might solve the problem.

If these methods fail to resolve the issue, the next step, unfortunately, is to format and reinstall your Windows.