My first reaction would be to cheer, since I never liked Media Manager, but seriously if MM won't work then you likely have a bad install.
Now the installer for EMC 10 could be called "unfortunate". It seems prone to falling over if conditions are not quite right, and it clutters your system with all sorts of garbage which upset further attempts to install. An ordinary reinstall isn't much use. Often the only thing which will straighten it out is a "clean install" which takes out the garbage prior to a fresh install. Some times folks have found they need to do the "clean install" routine a couple of times to get everything right. It's a real pain, but it's worth the effort.
The instructions for a clean install of EMC 10 in Vista are
HERE, and the instructions for EMC 10 in XP are
HERE.You are recommended to print them out and follow them
to the letter.The Repairer is a specific cure for a specific problem caused by using efficient registry cleaners. It won't help you with this problem you're having.
Regards,
Brendon