What to change for dual-boot if Win 7 is installed AFTER Win 10?

Assume I got a computer with a pre-installed Windows 10.
I want to additional install (64bit) Win 7 on it for dual-boot.

So I shrink some partitions, create a new primary partition and install Windows into it.

Unfortunately no menu appears at startup asking me whether I want to boot from Win10 or Win7 partition.

What do I have to change (with EasyBCD)?

Does it matter if the system is UEFI oder UEFI(CSM) based?

Does it matter if the hard disk is GPT or MBR based?

Thank you


Knows where his towel is.
Staff member
Have you done this and now can only boot W7 ?
Or are you just thinking of doing it and planning ahead ?
I tried this a couple of weeks ago but then deleted Win 7 partition again.

Meanwhile I found EasyBCD.

But before restart dual boot installation I want to evaluate if a setup repair is possible with EasyBCD


Knows where his towel is.
Staff member
If you install an older Windows version after a newer, it will cause a problem (easily fixed) because Windows boot manager is backwards compatible i.e. a newer version will automatically find and dual-boot an older, but not vice versa. The older boot manager will see a newer Windows as invalid (digital signature problem).
It's circumventable, but the details will depend on your PC (MBR v GPT and UEFI v BIOS).
Detail your configuration and we'll take it from there.