Hello,
Sorry to post such probably stupid questions but...

I have a desktop running under Win10 and want to install Ubuntu24 on it, on a dedicated HD.
In the computer U have 6 hard disks, all used by the Windows system, MBR partition style and NTFS formatted.

I made a bootable USB disk with Ubuntu, and have 3 questions:

1- About dual boot. As I understood, GRUB will manage the boot. Will it work correctly with the MBR partition style for all disks ?

2- Will the other disks be concerned by the Ubuntu installation ? I remember that, maybe 15 years ago, I tried to install a Linux OS in a Windows desktop and it "initialized" ALL disks inside. Data was lost... I can of course physically unplug the disks, but...

3- Will I be able to use the other disks in the computer, currently used by Windows, with Ubuntu ? Data only, not software of course.
I read online that is it possible but the exact question is to know if, after using them with Ubuntu (for example writing some data), can I use them again with windows, with all "new" data written by Ubuntu, usable ?

Thank you!