My daughter has Vista, and she had to use the TS3InstallHelperUAC.rar. Maybe that will help you, too.
[edited to add link] http://www.modthesims.info/download.php?t=344611
[edited to add link] http://www.modthesims.info/download.php?t=344611
and the problem is solved. i actually forgot there was a second file. thanks for bringing that up. after downloading that, i did everything as i had done it before, and it worked. strange that putting both the files provided in a Mods/Packages file wouldnt work, but oh well. thank you for your help.