Black SOD-like situation. OS believes there's two monitors.

Alienware X51 upgrade from Windows 8.1

I installed. Go back to computer, screen is black. I move the mouse around and notice the cursor can be seen. I also realize there's a monitor recognized by the OS to the left of my one and only real monitor. I attempted many ways to login and finally was able to do it blindly. Now, the OS still believes there's another monitor. I can see the Taskbar but any opened windows cannot be seen on my monitor. So, i cannot see anything but the Taskbar and my cursor on my screen.

I tried unplugging my monitor and replugging it but it didn't work. I wanted to do a fresh install of Windows 10 but i don't have a key to put in, i upgraded from 8.1, and i wanted to keep my files. I chose that option but it told me to not do that and remove the install medium which made no sense; how can i reinstall the OS without the install medium. I cannot risk losing my files that are in the hard drive. I don't have another monitor to try.