If you have sound problem "failed to play test tone" on your Window 8 Pro, then no needs to need worry here we will show you that how can you fix this problem. There are several ways to fix this problem. First we suggest you to try to fix the problem with the most common method which is to restart the Windows Audio service. If your problem is still not solved after restarting, then follow the following steps to fix the problem.
5 Steps To Repair Sound Problem On Windows 8 Pro
Step 1:
First of all go to Windows “Start button” and choose Run. After that type regedit in the 'Open' text box.
Step 2:
Once the registry editor window is opened, you will then need to go to 'Computer\HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Ole and export the “Ole” folder to backup it.
Note: You should save file extension as .reg of the exported file to any other place that can be easily accessed for later use.
Step 3:
Now carefully delete the registry key 'DefaultAccessPermission'. Once again be careful and don't accidently modify any other settings in the registry.
Step 4:
Now restart your system. Now check the sound problem is fixed or not once the computer or tablet is restarted.
Step 5:
Finally you will need to re-import the registry file. Good luck!