Dual boot setup with pre-installed Windows 10 and cloned Windows 7dows

NavyLCDR said:

It does not matter if you copied the Windows 7 system partition (boot files) or not. You set up dual booting by adding Windows 7 to the boot menu that Windows 10 is booting from using the command I posted.

Already did that. I am able to choose Windows 7 when prompted to choose an OS.
However, the problem now is I can't run Windows 7... it brings me to a black screen with the message "cannot boot windows 7. autocheck not found"

I tried Repair via Windows 7 disk installer, but it only detected my Windows 10, which it rightfully declined to repair.

I tried syspreping the Windows 7 installation. It failed.
Since it's very troublesome to dual boot a Windows 7 OS on a Windows 10 laptop, I calling it quits.

NavyLCDR said:

The first question is: was the Windows 7 that you cloned an OEM licensed Windows 7 (came with the computer) or was it a retail Windows 7 that you purchased a license for. If it was an OEM licensed Windows 7, then moving that to a new computer to dual boot with violates the End Users License Agreement and we can't offer any help to do that.

If the Windows 7 that you transferred is a full retail copy, then:
In Windows 10, the Windows 7 partition should have been assigned a drive letter. Let's say it got G:\. Right click on the start icon in Windows 10. Select Command Prompt (Admin). In the Command Prompt (Admin) window enter:

BCDBOOT G:\Windows /d /addlast

The path in red will be to the drive letter and Windows folder of the Windows 7 partition. Also recommend turning off Windows 10 fast startup:
Fast Startup - Turn On or Off in Windows 10 - Windows 10 Forums

Restart the computer.

I'll have to re try that BCDBOOT command on a laptop. Let's see how it turns out.

ajfudge said:

I tried syspreping the Windows 7 installation. It failed.
Since it's very troublesome to dual boot a Windows 7 OS on a Windows 10 laptop, I calling it quits.

Yes, at times its booting issue but a lot of times Drivers/ GOP support etc.

topgundcp said:

FYI. Unlike Win8/10. It is easy just to create a backup image then restore to the new PC, you'd get a screen: getting your devices ready... then Windows will re-install all the drivers needed. Doing this with Windows 7 will result in BSOD. In addition, your new PC probably set up with UEFI partition scheme and AHCI enabled so you must re-install Windows 7 with SP1 in UEFI mode for it to work.

Is there any way to "force UEFI mode install" when you installed the Win 7 to partition using DISM:
i.e. DISM /Apply Image - Or it would depend on the bcdboot commands after the DISM apply?

topgundcp said:

UEFI (Unified Extensible Firmware Interface) - Install Windows 7 with - Windows 7 Help Forums

Thanks. But, this method does not say anything about DISM based Wn 7 installation and how to enable it to boot/ run via UEFI mode? Thats kinda what i was asking.