Software Center thinks Application is already installed

I used the Software Center to install an application (SolidWorks 2014) but the system crashed while it was installing due to a lack of room on the hard drive.  I cleared all remnants of this program but when I tried to install it again the Software Center will not do it because it says the application is already installed.  The application is clearly not installed if you look at the program manager.  What do I do?