It's not good when a program does'nt uninstall completely so the best thing to do is try to manually delete as much as poss, then go get ccleaner or easycleaner (it's free). I use ccleaner, then by cliking on the registry button run the program and untick all except what is associated with whatever prog you have deleted,anything you do not recognise do not delete, also use IE folder search function and create a shortcut to the desktop of the prefetch folder, then delete all the contents of that folder (DO NOT DELETE THE PHYSICAL FOLDER ONLY THE CONTENTS OF IT)

PS: RE: upgrading of window blinds ,you have to uninstall older versions first the best way is by using stardock central as it will do it automatically or if you don't be sure to delete all that is associated with the older versions it's no diff to any new version of a prog that your upgrading too, remember it's not an update it's an upgrade there's a big diff