Hi Dskrobow,
Thank you for posting your query in Microsoft Community Forums.
From the issue description, I understand that you are facing issues with playing media files on Windows Media Player on Windows 7 computer.
I understand it must be frustrating, but rest assured, we are here to help you and guide you in the right direction.
"Server execution failed" should mean that "wmplayer.exe" is still running or shutting down at that point. This error may also cause due to the incorrect registry setting.
To trouble this Windows Media Player issue, I would suggest you to try these methods and check if it works.
Method 1
Run the Windows media player troubleshooter and check.
Open the Windows Media Player Settings troubleshooter
http://windows.microsoft.com/en-US/windows7/Open-the-Windows-Media-Player-Settings-troubleshooter
Method 2
a) Click on Start and in the search bar type cmd.exe
b) Right click on cmd.exe and click on Run as Administrator
c) In the command prompt type the following command
net localgroup "Administrators" "NT Authority\Local Service" /add
d) Press enter and restart the computer
e) Check if you are able to play the files in Windows media player.
If the issue persists, try the following steps:
Method 3
Restart Windows Media Player Network Sharing Service
a) Click the Start Button, type "services.msc" (without quotes) in Start Search box, and press Enter.
b) Double click the service "Windows Media Player Network Sharing Service".
c) Click on the "General" tab; make sure the "Startup Type" is "Automatic" or "Manual". Then please click the "Start" button under "Service Status" to start the service.
d) Click OK.
If it has been started, please stop it, restart the computer and then restart the service.
If the issue persists, try Clean Boot mode.
Method 4
Put the computer in Clean Boot state to see if there is any software conflict as clean boot helps in eliminating software conflicts.
http://support.microsoft.com/kb/929135
Note: After clean boot troubleshooting step, refer to “How to reset the computer to start as usual after troubleshooting with clean boot” from above article.
Perform these steps and let us know if you need further assistance. I will be glad to help you.