First check whether you have enabled system restore. Just right click the icon "My computer" on the desktop, select "Properties". In the opened window select the tab "system Restore". If the line "turn Off system restore on all drives" is not set by a bird, all right, you can start the recovery procedure.
Open "start" - "All programs" - "Accessories" - "system tools" - "system Restore". In the opened window must be marked "Restoring an earlier state of the computer." Click "Next" in the new window, select the calendar day are marked in bold – that as of this day, you can try to restore the system. Again click "Next", read the warning and start the recovery process.
You should know that the above-described recovery helps not always, in many cases, to roll back the system to a working state is not possible. In this case, try to reinstall the broken components. Open "start" - "control Panel" - "add or remove programs". Select "Windows components". In the opened window, locate the line "Windows Media Player" and remove the bird. Click "Next" player will be deleted. Then restart the computer.
Now re-install Windows Media. Reopen the Windows components and put a bird in front of the line "Windows Media Player", click "Next". Try to play a music file – the player should work.
In that case, if the fault is serious, and restore the player has failed, you must install it again. This will require the installation file, locate the latest version of the player. Run the installation file and follow all the instructions. If you have a licensed operating system, any difficulties should arise. When using unlicensed Windows installations may cause problems, as the installer will authenticate with the OS. In this case, replace the operating system license, or use other players, e.g. Winamp.