You have to remove the old one completely ..and this way you will get rid of any settings ...and all that ..to do that get into the control panel ..add/remove software ..(or programs .. for 7) and in there remove (uninstall ) the program completely ....
After that ,,go to C drive /program files ...and look for the folder with the program's name on it..and delete it ..so that no ..settings from the old installation will remain ..Also look for any folder named by its manufacturer..or subfolders with the program's name (I mean in there that may not be a folder with the program's name ..but under another ...and only inside to have a folder with the program's settings ..In this case delete all director that may be related..)
After that restart the computer ..and install a clean version of the program ..and give it a try ..