Install Shield error 5006 when trying to uninstall The Sims 3 base game

My C: drive is too full to add anything else to it or Windows might not work.  I have the Sims 3 installed on f: drive which is a partition on a 1.5 Tbyte USB drive that I created for windows to use for games to save space on C:.  When I ran the update for the sims it started writting to C:. I had to use [CTRL][ALT][DEL] to stop it.  Then the game wouldn't run!  I thought I probaley messed up the install so I began uninstalling the game but when I tried to uninstall the base game -after uninstalling the stuff and expansion packs-, I got Install shield error 5006!  How do I fix this?  Maybe edit the registry? When I get this fixed how do I tell the patches to install to F:?