For multi booting different versions of Windows I would suggest Boot-US boot manager. It can "true hide" primary partitions so that one instance of Windows won't
be able to see any other instance and mess around with it, as explained here:
https://www.boot-us.de/eng/tips_w05.htm
http://reboot.pro/topic/19532-how-to-true-hide-a-partition/
Also, the tip below might be useful if you decide to clone a disk or a partition with some disk imaging application (Acronis, Clonezilla, etc):
https://www.boot-us.de/eng/tips_w06.htm
Just to give you an example of what is possible, here is my layout:
Disk #1
Primary Partition 1: Windows XP
Primary Partition 2: Windows 7
Primary Partition 3: POSReady 2009
Disk #2
Primary Partition 1: BartPE
Primary Partition 2: empty
Primary Partition 3: empty
And here is an example of boot screen with Boot-US code installed in MBR:
https://postimg.cc/ygFJTWmk