Question Does Windows 10 Duel Boot affect the bootsector of another drive?

[ItsFlybye]

Say I have a fully functioning copy of Windows 7 on Drive A. I Want to install Drive B with Windows 10 to test on. Setting up where to install Windows 10 during the setup is pretty easy. What I would like to know is if I use Windows 10 boot utility to choose between Windows 10 or 7, would it affect the mbr on Drive A? If things don't work out as expected with Windows 10, I would like to be able to just disconnect Drive B and boot up into Windows 7 without having to do any repairs on Drive A to make it bootable again.

 

[ArisVer]

Since no one answered, I have a suggestion for you (I am out of the dual boot loop since 20 years ago).

Drawback. You have to select boot device from BIOS.
Positive. Much better than dual boot, your disks remain clear of each other, no worries about messing the boot records.

Remove your working Windows 7 disk (Drive A).
Connect second disk (Drive B) and install Windows 10.
After installation is finished, connect the first disk as well.
Choose from BIOS your boot disk.

 

[ItsFlybye]

Actually, that is not a drawback at all. That is the way I have always done it.

I just never used one of the "software" options like the Windows Boot Manager because I was always worried if it tampered with the other drive's mbr. I always figured selecting the boot drive in the BIOS was the safest way of keeping the integrity of the MBR alive. So I will keep doing what I have been doing. ty.