First of all download Clean Installer and SimPe. With SimPe you can pack sims that you have created in game. You can move your "downloadfolder" to the desktop before you uninstall the game. That way you'll keep your downloads. If there is one file that are creating trouble then try using Clean Installer to go through your downloadfolder, and remove new files and empty packages. You can also use Delphy's download organizer to help you sort your downloads and find the file that is causing the problem.