help I can't see my computer screen

I was messing around with the graphics properties on my old computer to use it with my TV. The TV required 1440x900 and i couldn't find that - in attempting other sizes closer to that my graphics don't work anymore...the monitor simply says not support or nothing at all. I tried safe mode and that didn't work. What do I do? Please help!:confused

 

Are you still connected to the TV after a restart?

If not, can you confirm that you've tried safe mode while disconnected from the TV? (I see that you've tried safe mode, but I need to make sure of the context in which you did that, to eliminate some possibilities)

If that still doesn't work, is it possible for you to try another monitor, with the TV disconnected?