Windows media player gives error "Server execution failed" after trying to play file
Solution 1:
Try going into services, scroll down to Windows Media Player Network Sharing, click 'restart'. Then restart your Computer. Worked for me so far.
edit: I just found another solution that I did not yet try. But if the problem returns, I´m going to try it.
Go to Control Panel\Programs and Features\Turn Windows features on or off\Uncheck all Media Features\Reboot\recheck WMP only.
Solution 2:
I had this problem before and I discovered that it was because Windows Media Player was timing out trying to read the hard drive. I finally switched hard drives and now I haven't had this problem again.