Are you running an antivirus software? If so, make sure you've allowed all processes of moviecollector... it's possibly that your antivirus is getting in the way. Either that, or you could be having issues with your virtual memory. Try downloading a program like CCleaner to clean up unwanted/unneeded files and data entries. With as many install/uninstalls you've done, it's very possible that you have some tangled registry entries.
Run CCleaner -after- you've uninstalled moviecollector. And also run Disk Cleanup from within Windows. Completely shutdown your computer after that, then boot back up and install moviecollector and see what it does. *crosses fingers*
CCleaner - http://www.piriform.com/ccleaner