It is not necessary to format your hard drive.

If you just plainly 'deleted' the TSF folder by itself, all the registry and installation entries are still existant, and the case could be that the Jazz 2 installation program "recognizes" that it has been previously installed and doesn't need to install again. Which brings me to a quick reminder; don't delete the program just plainly with a delete command. Instead, uninstall the program so that all registry entries are removed.