Trouble loading movie maker 2

I recently got hit with a nasty system wide virus
(win32.pinfi) that attacked most of my .exe files
including Movie Maker 2 executable.

I have managed to wipe the virus off the puter but am
having heaps of issues after same.

One issue was with my older installation of Movie Maker 2
on XP Professional where I got intermittent errors with
streaming video and the gui would crash when trying to use
any transitions between files.

I tried to hack the registry to remove Movie Maker 2 only
to later find it is rather a unique installation (read:
dozens of registry entries).

I tried downloading the Movie Maker 2 .exe again only to
have Movie Maker 1 launch each and every time.

Any hints/ideas on how to blow the Movie Maker 1 away and
update with Movie Maker 2 again?

Cheers
Wudman