I play WAW at 1280x720 resolution, and it used to run 'fullscreen' (i.e. no black border around the edges), however after hooking up my PC to my TV it messed with the resolution and after switching back to my desktop monitor it now has a black border around the screen which is starting to annoy me. I can only get rid of it using the max resolution (1920x1080) which unfortunately my PC can't handle  I had this problem before and I managed to fix it somehow but I cant remember how I did it, anyone have any ideas?

Your TV should have an options menu for resolution settings.

16:9 Full means the screen will always be stretched out and you will never have black borders. Try finding that.
You may currently be running 16:9 Original or what ever.

Go to the menu for you TV and play around with the picture settings and you should be able to fix it. You don't need to change your IN-GAME dimensions.

Hope that helps. 

Your TV should have an options menu for resolution settings.

16:9 Full means the screen will always be stretched out and you will never have black borders. Try finding that.
You may currently be running 16:9 Original or what ever.

Go to the menu for you TV and play around with the picture settings and you should be able to fix it. You don't need to change your IN-GAME dimensions.

Hope that helps. 

I tried that but it's not the monitor, it's WAW, it actually fixed itself randomly the other day for a while but went back again, no-one have any clue about this?