Sounds like a manual uninstall is necessary.
I'd delete the program folder and all the registry keys associated with that program. As always, make a backup before messing with your registry.
Make a backup before deleting anything just in case you screw something up. Search for WinDVD entries in SOFTWARE under HKEY_LOCAL_MACHINE. You may also use the Edit (menu) and Find Next to locate any other windvd entries.
If you run Registry Mechanic, it would probably get rid of those other entries seeing the program is uninstalled/missing. Any entry that is associated with WinDVD, I'd delete.