skip64, lets see if I can help you out here. First thing is you must be a administrator account. Uninstall QT using the add\remove control panel. Then do a search of the computer for any QT files and folders that were left over and delete them. Also go to C:\WINDOWS\system32 and delete QuickTime qts and QuickTimeVR qtx.
If at some point K-Lite mega codec pack or QuickTime Alternative was installed on the computer they must be removed, they have been known to cause a problem.
You mentioned error 2330, which I have no idea what that is other than reading something about corrupt registry. CC-Cleaner if I have the name right, is supposedly free, someone did post here one time that it helped them, myself I would use it as a last resort for the registry, but that's just my opinion