OS: XP SP3 I can't run either WMP or Limewire player to play MP4 files.

From CCleaner Registry Cleaner: Unused File Extension .mp4 HKCU\Software\Microsoft\Windows\CurrentVersion\Exp lorer\FileExts\.mp4 (NOT FIXED)
I just left this one alone.

In Explorer I just get the generic file icon with unknown file type.

Any ideas?
Rodney Wise
***EDIT***