Un-installation issue

Hi All,

  Need help, Please advise, Unable to start solidworks 2009 after try to roll back from SP4 to SP3

I didn't return the Solidworks license while during the roll back. 

Error message :

The patch package could not be opened, verify that the patch package exists and that you can access it, or contact the application vendor to verify that this is a valid windows installer patch package

What should I do now ?  Appreciate someone could help.

Thank you.SolidworksAdministration