If you have an older installation file (e.g., for Windows Vista), you can force it to run on Windows 7 .

This is the most reliable way to find a compatible driver if an official one is missing . Open the and click on Devices and Printers .

: A third-party application that supports many legacy scanners, including the HP ScanJet 3500c , even when official drivers are missing .

: A built-in Windows 7 utility that may recognize the scanner if a basic "plug-and-play" driver was successfully installed .

Click or Add a device at the top of the window . Select The printer/device that I want isn't listed .