Dual Boot Win 10 & 7

I run Win 10 (1803) on my main PC
I was also running Win 10 (1803) on a secondary PC.
I had a 3rd PC running Win 7 (for certain older apps I need)
The PC running 7 started to have major hardware problems, so I had to junk it, but kept the HDD with 7 and my programs.
I installed the HDD onto my 2nd PC and tried to dual boot after installing EasyBCD.
Not working - I get the choice on startup Win 10 or 7, but when I choose 7 I get the welcome screen then the flash of a blue screen and it reboots.
Is there a way to repair the boot on the Win 7 HDD ?

Probably not much you can do without rebooting Windows 7 on the old PC. There are steps you have to take in Windows 7 before you move it to another computer. Maybe you could not it in a virtual machine.

Thanks - I guess it's a case of having to reinstall Win 7 on the same HDD plus the programs I need while it's connected to the win 10 PC.

bro67 said:

Just do a repair of 7 by booting with the Windows 7 DVD/USB. System Recovery Options: Guide for Windows Vista, 7, 8, 8.1 and 10

That won't fix BSOD issues when booting into Windows 7. It's a driver issue. When moving Windows 7 to new hardware, sysprep must first be run to clear out all the existing hardware drivers in device manager so that the new hardware can be detected and drivers installed when the Windows 7 is moved to a new computer. Windows 10 handles this much better. More than likely, it is the SATA controller driver that is causing the issue. Unfortunately, the only real way to correct the issue is to uninstall the old controller driver before moving the Windows 7. @Pendragon could go into UEFI (BIOS) settings and maybe change the SATA controller to IDE mode instead of AHCI home. That might allow Windows 7 to boot, and then @Pendragon could delete the IDE controller in Windows 7 device manager, reboot the computer, return to UEFI (BIOS) settings, and change the SATA controller back to AHCI.

OK now there is a further problem.
I reinstalled Win 7 on the extra drive (after formatting)
The installation went OK and can boot in to either drive.
The problem is Win 7 cannot find a network adapter and says there is no network available.
If I go back to Win 10 the network is up and running.
Is there a fix for this ?

Install the Windows 7 driver for the network adapter in the computer.

The network adapter is on the motherboard (Asrock) how do I install it ?

- - - Updated - - -

OK found the Asrock CD installing now