Dual Boot Windows 7 And 10

I have been running Windows 7 on a Dell OptiPlex 960. The 960 has 2 hard drives. I made a system image, (Macrium) of drive C, (Windows 7) I then installed that image on the second hard drive (F). I unplugged the first hard drive, (C) and booted into second drive, (F), fired up Windows 7, and did upgrade to Windows 10. Upgrade went as it should. Can run Windows 10 on (F) with no problems. Now I reconnect hard drive (C) . Fire up the 960, go to bios and select (F) drive. Windows 10. No go. Screen says there is a problem, and Windows 10 does not load. However, if I fire up the 960, and go to bios, and select (C) drive Windows 7 starts. So why won't Windows 10 on second hard drive work?

Since what you are wanting to do violates the End Users License Agreement for Windows, we can't really help you here at Tenforums because it violates the forum rules.

NavyLCDR said:

Since what you are wanting to do violates the End Users License Agreement for Windows, we can't really help you here at Tenforums because it violates the forum rules.

Did not know that.

I was going to suggest virtualization, instead of dual-booting, but that also would require two licenses in your case. That's the deal with the free upgrade, is that it replaces the license for the previous OS. So, buy doing the upgrade process, you invalidated your Windows 7 license.

Most of us have ended up doing a clean install of 10 once the upgrade process has finished and activated. Sounds like this might be a great time to do so.