wont launch

I need help. Everytime I open Hammer it just doesn't open. Instead, it creates a MDMP file. Does anybody have a clue on how to fix hammer? I've already tried verifying the game cache and it still wont work...

I'm new to map making and I've just created my first one but I've run into a wall. Any time I decide to run my map it brings up the grey background screen of TF2 and closes out without going further. Ive checked for leaks which there are none and have been around several threads but I can't...