This is a fairly common issue caused by an incomplete uninstallation. Many times it is due to a poorly designed uninstall method. In order to remove the program, you will need to delete the entry from the Windows Registry. Prior to making any changes in the Registry, be sure to make a backup copy.
How to back up the Windows Registry
Invalid Entry Removal Instructions:
1. Go to Start>> Run. Type in: regedit [Enter] or click OK.
2. Navigate to the following registry key:
HKEY_LOCAL_MACHINE\Software\Microsoft\Windows\CurrentVersion\Uninstall
3. Expand the Uninstall entry by clicking the "+" symbol.
4. Below, you will now see all of the programs listed in the Add/Remove Programs menu. At the start of the list, you may see many {GUID} entries (Globally Unique IDentifier) which are a random set of letters and numbers encompassed in brackets ({ }). In order to know what program these are, click once on the {GUID} and notice its "DisplayName" in the right pane (see fig.1).
5. If the invalid entry you are searching for is not one the {GUID} entries, keep scrolling the Uninstall list until you find it.
6. Once you have located the invalid entry, save the Registry entry to a file, then go ahead and delete the entry by simply right clicking it and select delete.