1. Goto - start - run
2. Type regedit - click ok
3. Navigate to - HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\P layer\RecentFileList
4. Look at the window panel on the right - delete all that you wish removed from media player recent list
alternatively you can just get ccleaner from ccleaner.com; under the applications tab you can select the option to clear most recently accessed files in many common programs..