How to get to the Boot Manager setup correctly

[warp4dennis]

Hi All:
I've tried with Win 7 several times to use a Boot Manager in order to access a second
Operating System that is installed on my PC, but without success.
And now I want to remove Win 7 and replace it with Win 10, but I still want to have access
to the other OS as well as Win 10.
I have heard that Win 10 comes with a BM, but in my readings I haven't found anything
about it at all.
Is there anybody at this Service, who reads this e-mail of mine, who can tell me how it's
done, or can direct me to where I can find information about how I should setup my PC
so that I can access, one after the other, the Operating Systems that are to be on my
PC?


Thomas

 

[samuria]

We need more info in order to help what other o/s are you using uefi, gpt, or mbr and secure boot?

 

[iko22]

As a general rule, if you want boot manager to show boot options, then you need all disk drives present when you do the install.

If you have disconnected the main Windows 7 drive, prior to installing your "other" operating system, then the installation process wont find the boot manager - but will create a new boot manager instead, resulting in two boot managers that only recognise one OS each.

What happens if you temporally disconnect the Windows 7 drive, does the computer boot into the "other" operating system?