How to Turn on the USB Port for a Scanner
By Daniel Hatter
For any USB, or Universal Serial Bus, device to work, the USB controller must be enabled on the computer to which it is connected. USB controllers do exactly what their name suggests -- they control a computer's USB ports. If, for example, you disabled the USB controller on a business computer to prevent unauthorized USB device connections, you will need to turn it back on before you can use any of its USB ports. To connect a USB scanner to the computer, re-enable the computer's USB controller.
Open the Device Manager. In Windows 8, right-click the "Computer" icon on the desktop, select "Properties" and then click "Device Manager" in the left pane. In Windows 7, the "Computer" icon can be found in the Start menu if it's not on the desktop. Alternatively, open the Start screen (Windows 8) or Start menu (Windows 7), type "devmgmt.msc" and press "Enter."
Double-click the "Universal Serial Bus controllers" category at the bottom of the Device Manager window to expand it. Click the "Scan for hardware changes" button in the menu bar to retrieve up-to-date hardware information; there will be a black icon next to each USB controller that is disabled.
Right-click the disabled USB controllers one at a time and select "Enable" from the context menu. Once they are all enabled, close the Device Manager and connect the scanner to one of the computer's USB ports. Turn on the scanner; the computer will now recognize it.
You must be logged in to the computer with an administrative user account to make changes in the Device Manager.
Daniel Hatter began writing professionally in 2008. His writing focuses on topics in computers, Web design, software development and technology. He earned his Bachelor of Arts in media and game development and information technology at the University of Wisconsin-Whitewater.