screen locks up

[2shad4u]

i could exit the game fine for a few weeks, now all of a sudden the screen freeze on quit started back up........any ideas ?

[2shad4u]

may i add if any help to figure out the problem, when the screen locks up forcing me to restart the tint of the screen goes a bit darker...................i cant go out by using quit, i cant alt f4, i can only sometimes alt tab then close but even then it freezes up normally, or sometimes when i can close it with alt tab i get an AH error