Listo

Grax por todo,, ya lo encontre, aquí lo dejo por si alguien lo nesecita.
To remove the play list entries:
1. Start Registry Editor (Regedt32.exe).
2. Locate, and then click the following registry key:
HKEY_CURRENT_USER\Software\Microsoft\MediaPlayer\Player\RecentFileList
3. If you are using Windows Media Player 6.4, click RecentURLList, and then click Delete on the Edit menu.
If you are using either Windows Media Player 7, 7.1, or Windows Media Player for Windows XP, click RecentFileList, and then click Delete on the Edit menu.
4. Quit Registry Editor.