Want some help with "dual boot"

General system Newbie
1

Hi. I know this is technically a repeat topic, and honestly don’t even know if this counts as dual boot, but I’m not very well versed in this stuff and am really just trying to be safe.

I have two ssds; windows 11 is already installed on one and, right now at least, pop!_os is installed on the other. I want to replace pop!_os with endeavour. Here’s the thing: when I installed pop!_os, for some reason that is entirely beyond my understanding, it completely destroyed my ability to boot windows 11 from my other ssd. All of my files were still there, so I backed them up and had to reinstall windows completely. My point being: I have absolutely no idea what caused this and want to do what I can to prevent it from happening again.

Is there any reason trying to install endeavour onto my ssd (which currently houses pop, not windows 11) could somehow keep me from booting to windows 11 from my other ssd? And is there any way to ensure that this doesn’t happen? I had someone suggest that I remove my windows 11 drive from my computer, installing endeavour, and then putting it back in; would this work? Could it cause issues with booting? Any suggestions are appreciated!

P.S. I lied when I said I have “no idea” why my pop install messed everything up; I suspect it could have something to do with the USB I booted off of, since I used the same one for my windows 11 reinstall and was plagued with problem after problem after problem (it was extremely slow; rufus took 11 hours to put the windows iso onto it) until I bought a new USB, which then worked the first time no problems.

2

It is probably the EFI partition.

If you want them to be completely separate, be sure to use the EFI partition on the disk you are installing EOS onto.

3

What I have seen others do is to install the GRUB or SystemD boot loader, which will be used to boot linux, on the same SSD as that on Linux. So let us take your example. Let us assume that you have two SSDs, /dev/sda and /dev/sdb. Let us also further assume that you have Windows installed on /dev/sda. It dont matter what version of Windows, I will try to keep it generic. And finally you want to install Linux (EndevaourOS or pop!_os or Arch or something else ) on the /dev/sdb. If such is a scenario, I will end up creating 4 partitions or more on /dev/sdb as given below

  1. /boot - ext4/3/2
  2. /boot/efi - FAT32
  3. / - ext4/3/2 (this is the root partition)
  4. /swap

If need you can add partitions for /home and other directories too.

And I would install GRUB on the partition /boot of /dev/sdb disk. For better protection I would also label the partition as bootLinux or something similar but which is 11 characters or less. This labeling is optional but is very good to have in case of emergencies or recovery.
What I will not do is install GRUB on /dev/sda where Windows is installed.

However if you have installed GRUB on /dev/sda with Linux installed on /dev/sdb then you might end up the scenario that you have outlined. Keep Windows and their associated boot loaders on different disk. Dont mix them up.

Hope this helps.