In order to properly uninstall the demo of Drive Genius 3, you will need to manually uninstall it.
To manually uninstall Drive Genius 3 delete the following files and folders at the end of the paths listed below. Double click on your "Mac HD" drive to start the path.
/Library/Application Support/DriveGenius (folder)
/Applications/Drive Genius 3.app (icon)
If you are running OS X Lion, Mountain Lion, or Mavericks the last three files/folders are located in the user's
Library folder which is hidden by the operating system. You can temporarily access this folder by opening a Finder window and pressing Command+Shift+G. This will bring up "Go to the folder", enter
~/Library and click go.
/Users/Library/Application Support/DriveGenius (folder)
Now you will need to restart your computer.
You can contact Drive Genius support at (877)477-6763 [press 2 for support].