I have no idea what I did wrong......

first..... darktable was messing up so I decided to upgrade Mint to the newest version to see if that would fix it.

I put the disk in and installed it but upon restarting the live disk loaded again. Then I tried installing it again but it would load the OS from the live disk (I guess) but then when the gui started it would access the hard disk drive. I then tried putting a previous version on and this time it installed (instead of failing) but when I restart the computer it loaded the live disk (which was not in the computer at the time. What in the world did I do?