Linux and windows dual boot problems: A journey

I tried to install Linux mint because I can’t deal with breaking my setup every three months. Now, I have a lot of different hard drive and only wanted to install Linux on one of them. So, I unplugged every hard drive except the one I wanted to install mint on. I then installed Linux mint and everything seemed fine, until I put the hard drives back and I saw that I now can’t boot to windows any more for some reason. It looks like the MBR of windows is gone.
I will keep you guys updated with my progress in repairing my partition if I’m ever get successful.

Right now, the next step forward is creating a windows bootable usb to try to repair the partition.

UDPATE: I’m now creating the windows bootable with woeUSB which for some reason wouldn’t work from the GUI. It was complaining about reaching the 4gig limit of FAT 32. That’s weird because my usb key is formated in NTFS. Anyway I launched WoeUsb from the command line instead with this command instead
woeusb --target-filesystem NTFS --device Win10_1809Oct_EnglishInternational_x64.iso /dev/sda
it’s taking a bit but I’ll keep you guys updated

So I looked at the partitions in Gparted and the master boot record is literally gone. Now, some would say this is a sign and that I need to embrace the Linux world fully and just not touch windows again. BUT, I still like to play games that only work on windows so I need my windows install and since my Linux install is a fresh one, I’ll just re install windows which will probably wipe the mint and reinstall Linux mint afterwards.

Well i guess since you installed linux mint without the option to install it next to windows.
Because you unplugged the windows drives.
So Grub or bootloader basically doesnt know that there is another OS drive arround.
I guess its fixable.

When you put the OSes on separate drives without knowledge of one another, you usually have to select which drive you want to boot from. Generally you would select which one you are most likely to want to boot in to as the first drive UEFI/BIOS attempts to boot from, and use whatever hotkey for the boot selection menu to select the other drive when you want it. Did you try disconnecting all but the Windows drive to see if it would boot?