wc2 demo not working

[username12345]

I downloaded wc2 demo and put it on an old pc of mine. So I start the game (after installing) go in to the campaign start it but I can only move my cursor across the top part of the screen. I reinstall and the same thing so I do it a few more times. then I decide well this kinda sucks but I can still use hotkeys and stuff. So I play a bit then all of a sudden I can only move my cursor across the top left quarter of the screen. It moves fine on the desktop and stuff plus I've tried another mouse but the same thing . Help please.


Thanks