Get "upgrade patch cannot be installed by Windows Installer service..." message when installing p (59571)

When trying to install a patch, I get the following error message.

"The upgrade patch cannot be installed by Windows Installer service because the program to be upgraded may be missing or the upgrade patch may update a different version of the program. Verify that the program to be upgraded exists on your computer and that you have the correct upgrade patch."

Check to make sure you do not already have the most recent install of Toad for Oracle installed. This message is usually received when you are trying to apply a patch that is an older version of Toad than the version you currently have installed.