Get your self a program like Add/Remove Plus 2003 it should be able to fix your problem. You must have had an install problem the first time you installed Solidworks, didnt initiate the uninstaller.
heres a link and some details for this program

LINK:

Add/Remove Plus! 2003 is a solution designed for all Windows operating systems (Windows XP/2000/NT/Me/98/95) that offers an easier and better way to uninstall programs you no longer want on your computer.
When you want to uninstall a program, all you have to do is to double click the "Uninstall Programs" icon on your Desktop. Add/Remove Plus! 2003 will display each program that is installed on your computer and help you quickly find the program you want to remove. Then all you have to do is highlight the program name and click "Uninstall". Add/Remove Plus! 2003 will run the uninstall routine and make sure the program is removed from the list. This way users can easily get rid of all unnecessary programs for good.
Add/Remove Plus! 2003 helps you maintain a cleaner computer and a cleaner registry. The product is also intelligent enough to indicate the programs that have been already removed from your computer, but were left behind in the list by misbehaved uninstallers. These programs can be removed from the list to reduce clutter and make it easier to find and uninstall other programs in the future.