Screen Resolution Change, Border Around Screen, Etc

for the past month i have had an issue where before the log in screen would show, it would be a blank screen with a cursor, that i could move. (It worked normal in safe mode) I normally would just ignore this problem and it seemed to go back to normal after a little while. Well yesterday it didn't go away, so i went online looking for a solution, in safe mode. I've read to disable/enable drivers, re-install drivers, just plenty of things. And the result of all this is that my screen resolution wont go back to normal, and there is a black border around my screen, around a half inch. Also, my computer has been running EXTREME slow lately.