I was using image editor as a kind of generic term. Either way there really aren’t many options.
By the way, did you get Krita from their website or F-Droid? The version on the website is newer, so if you haven’t already tried that version you could try it as a last ditch effort.
Since they’re going to be on separate drives there should be no problems. Literally the only time you have to worry about Windows eating your bootloader is when they’re on the same drive.