So I'm thinking it is still not installed right. Is there a reason windows is blocking, or is the OS not able to handle modern hardware and graphics of a simple windows computer? What makes this frustrating is that the laptops are only 5 and 7 years old and they are running great on Zorin OS, but so far no luck dual booting after what I would say was way past two dozen re-installs. Willing to start again if I can find a way to make it stick and just a start up selection. Help please.