Shrek

So recently i decided to reinstall Halo 2, since it used to be one of my favourite games. It installed fine, but the loading screen and some textures in game are flashing and glitched out. The mouse also does not work, so I have to navigate the menus with arrow keys. In game the mouse is also very sluggish and unresponsive, which makes the game virtually unplayable. Has anyone encountered this problem before and have a fix? I am running Windows 7 64 bit. Thanks in advance.