I just installed an SSD in the second bay and started installing some games on it etc.
After noticing some issues with a couple of games, Overwatch wouldn't run at full screen etc. I updated the video drivers and then got the latest updates from NVidia as well. Then I updated the BIOS from 1.08 to 1.09.
When the computer rebooted it wouldn't boot into windows, gave me errors about trying to repair etc. Long story short, I got into the BIOS Settings with F2 and the BIOS update had changed the boot priority order of the two hard drives. It couldn't load windows because it was looking at the second drive instead of the primary drive.
I switched it back and saved the changes and was then able to reboot back into windows.
Not a problem/question but maybe it'll save someone else a little headache if it happens to them.
Chris