Sounds like you need to clean your registry. There are a two basic ways of doing this, by manually searching and removing anything related to Quicktime or iTunes (possibly Apple as well), or by downloading and running one of the many registry cleaners out there.

I'd recommend getting a registry cleaner, try RegSeeker. You should see a bit of an improvement in speed running a registry cleaner every week or two, but even if you only use it when you need to get rid of obselete entries in the registry it should be good.

If you want to manually edit your registry, type 'regedit' in the run box from your start menu, then F3 will bring up the search box. Once you've entered in your search terms, subsequent F3s will keep searching.

Make sure you backup your registry before making any changes, have a look here for one method.

Come visit us at RenderGods.

Ignore the shooty dog thing.