Solved black screen on win 7 - dual hard drives win 8.1 on other

Hey; When I try to boot to Win 7, I get the logo and then a black screen. I have tried all the repairs and nothing works. Win 8.1 is fine. Help and thank you.

Boot the Windows 8.1 DVD/USB disk or Repair USB disk.
http://www.eightforums.com/tutorials/2269-system-recovery-options-boot-windows-8-a.html
Open> command prompt.

Use the Rebuild BCD in this tutorial:
Use the Bootrec.exe tool in the Windows Recovery Environment to troubleshoot and repair startup issues in Windows

Black screen

I did not make myself clear. When I use Windows 8.1 everything works perfectly on the first hard drive. However, when I try to go into my other hard drive, which has Windows Seven, I get the black screen . I get the windows logo to come up and then it goes black except for the curser arrow running around the screen.

Was that Windows 7 originally installed on that PC? Did it ever work correctly?

Yes, it worked properly. I had a new motherboard installed and everything checked out. When I got home, the Windows 7 hard drive was not working.

If the new motherboard has a different chip-set than the old one its likely a driver issue. Have you tried F8 safe mode? A major hardware swap like that may require a reinstall.

Can't even get safe mode as an option on Win 7

Recheck all your Data/SATA and power cables to make sure they are connected firmly. So Windows 7 worked fine on the new motherboard before you took it home? Is the new motherboard different from the old one?

Yes, a new motherboard. Just returned from repair shop. Both hard drives worked fine. Came home and 7 still black. Crazy.

Unplug any external USB devices like printers and try again. It's either something you've added since getting home, or something got knocked around some how. That or Windows 8 did something to the Windows 7 drive file system.

Hey; That was the issue. Now I have to figure out how to plug the printer back in and have everything work properly.

I've seen other posts with similar problems. I don't recall if they actually found a solution. Make sure your drivers are up to date I guess.

Many thanks for taking the time to help.