HELP! Screen off center!

I've never had this issue in the past, and it was working fine earlier today, but now when i've just tried to play, it was like it. Basically, I can open launcher fine, it appears in the center of my screen as usual, then I can open it to the login screen normally... Then it gets weird. From the start its off to the side, with a black border on the left, which blanks out nearly half my screen... It doesn't just blank it out though, it makes it so its not shown - Like its off into the side? Sorry for not explaining this well.

Basically, its nearly half my screen in width, and all I can see is the left side of the game, from the Crossfire Logo in the top left (cutting off the very top of each letter), to the Item Shop, which only shows Item Sh.

Any ideas on how to fix it? I'd prefer not to re-download crossfire, but I guess I will if I absolutely have to. I can't see the exit button, so I have to Control - Alt - Delete out every time, which means I also can't change my screen width in there... HELP!

Also, my monitor is the HP f1905e, if that helps at all... Thanks in advance