Windows Registry
I had recurring issues with registering Bluetooth devices, where they would pair initially but refuse to connect again after a reboot. I couldn't remove the device from saved connections, and registry edits wouldn't save or persist. I'd have to completely uninstall the driver, change the registry, and reinstall the drivers, with restarts between each step, to get it to work for 1-2 days.
Now, having to troubleshoot isn't what turned me away from Windows to Linux. I knew I would run into that plenty on Linux as well, but I came to hate the registry. If I was going to have to go through all this trouble to get things to work, I might as well do it on a system I had more control over. I had worked with different distros on VMs and dual booting before, so when I built a new system, I just skipped Windows entirely.