My computer was working fine last night until I went to shut it down, then I got some sort of UI logon error and it wouldn't turn off. So I pressed the power button until it turned off. Now my screen is all messed up. I get a pop-up that says my resolution and color depth are set too low, but when I try to readjust it it remains the same. It basically looks like a greyscaled photo negative. However, everything looks fine in safe mode. How do I fix this?