Change windows enterprise back to windows 7. I would like to do one of two things. Someone installed windows enterprise on my new laptop 3 years ago over the windows 7 that came with the system. Now I want to give my computer away, but cannot use the re-installation disc because enterprise doesn't recognize it. I would like to either convert back to 7 so that my re-installation disc works or simply clean out my hard drive using enterprise to delete all of my personal information.