That scanner is not compatible with Windows 7. Source:http://www.microsoft.com/windows/compatibility/Windows-7/en-us/Details.aspx?type=Hardware&p=MUSTEK%20ScanExpress%201200%20UB%20Scanner&v=MUSTEK&uid=&pf=0&pi=3&c=Printers%20%26%20Scanners&sc=Scanners&os=32-bit
However you can try downloading the XP driver and try it run in compatibility mode. If that does not work you can either contact the manufacturer or buy a newer scanner. They are quite cheap.