I just upgraded my desktop to Windows 7 from XP pro 32 bit. Im running Autocad Electrical 2009. When I opened any old drawing files, they didnt display properly in model space paper space, and Autocad locked up if I moved the mouse around or tried zooming in an out. I took your suggestion of running the program in Windows XP compatibility mode and it seems to have fixed the problem. Thanks to all who posted help. I was worried I was gonna have to upgrade to the latest version. It would have been cheaper to buy a used PC and Windows XP pro license to keep the old version running, than pay for the upgrade from 2009 to 2013.