Picture this: you buy a car. You buy a new set of wheels/rims and a new radio system with Android and whatever. You also put some new carpets on the floor of the car. Now you need to take it for a simple routine maintenance and checkup at the car brand official shop. After a few hours you go back there to pick you car up and it has the stock wheels, stock radio, stock carpets and everything and you ask where the hell is your stuff and ALL of them on the shop look at you confused like if they never seen any different accessory on that car before other than the stock ones, or don't know what you are talking about. All they know is that the car is now "according to spec".
This is what it feels like after updating Windows with Linux in dual-boot on the same drive.
There was a time when Photoshop and other programs used a copy-protection scheme that overwrote parts of grub, causing the user not to be able to boot Linux or Windows.
They knew about it, and just DGAF. I don't remember their exact FAQ response, but it was something along the lines of "Photoshop is incompatible with GRUB. Don't dual boot if you use Photoshop."
Grub still has code for BIOS based installs that uses reed-solomon error correction at boot time to allow grub to continue to function even if parts of its core.img were clobbered by shitty copy protection schemes for Windows software.
If I dual boot windows, I tend to disconnect my Linux drive any time I do anything on the Windows side. Even installing Windows fresh using default settings, it managed to completely erase my Linux disk to put the Windows bootloader on it even though I selected a completely different disk for the Windows OS. Won't be making that mistake again. And by mistake I mean dual booting Windows. That pile of spaghetti code gets a VM.
i use a different drive for my windows installation because that happened to often,
and i swear it once managed to wipe the bootloader on the linux drive.
i have no idea how it did that,
but i avoided starting windows using the grub entry since then.
Having two drives is sometimes not enough, either. I have no idea why, but anytime Windows installs for the first time or goes through a major update (not the small security patches, but the periodic feature releases) there's a random D20 dice throw to determine if it will randomly decide to create the bootloader and recovery partitions in another drive, even though your main installation isn't there.
I kid you not, Windows 10 once decided that my external SSD enclosure was the best place to put the bootloader.
