Windows when it books does not have to ignore all file systems. That's why you backup what you can't lose.
Also, Microsoft NEVER implemented a way to add another intact OS and make it work. You have to dig around the internets and see what method you'll use next.
I gave up on this at the office and if we need to run XP, we have machines in storage for that.
I have a ssd that boots XP with lots of progs and settings over many years (don't want to reinstall it).
And i have another ssd that boots win7 from the same systems at a different time, with less stuff on there (less of a pain to reinstall).
I want to create a dual boot with them, but i rely on the XP drive heavily and don't want to mess anything up, so i have some questions;
If i just plugged both in, could one of the mbr be destroyed?
Would it allow me to manage them with a boot manager from whichever one i booted into? (not sure which the dominant one would be)
Could i manipulate the boot order in the bios favoring one or the other without changing any of the mbr?
any advice would be welcome, i have read about dual booting, but all the guides talk about install orders, none of them start with pre-installed drives that haven't technically seen each other yet.
thanks.

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