Double-click the WindowMizer.dmg file.
The .dmg file will add a disk icon on your desktop and open it, thus displaying the WindowMizer application and an alias to the Applications folder.
Drag the WindowMizer icon onto the Application folder icon.
This will copy WindowMizer to your Applications folder on your hard-disk. Once this step is complete, you can remove the disk image from your desktop by dragging it to the trash icon.
Launch WindowMizer and perform any required System settings configurations that you are notified of.