Right click and press, RUN AS administrator. If that doesn't work, then try to open it up manually, by going into the folder and pressing the original crossfire.exe not the shortcut, if that doesn't work, sorry to say but your gonna have to re-install. then it will work perfectly fine. If you have any settings that you want to keep, go into your folder and back up some stuff, then just copy it into the new folder after reinstalling. Good luck.