The operating system Microsoft Windows 7 allows the computer to shut off power to USB devices to save power. If you are using a laptop computer, this feature may help if you do not want USB-powered devices to draw off the computer's battery while the devices are not actively being used. On the other hand, this feature may cause problems with the operation of some USB powered devices, creating more of a headache than a help. Windows lets you turn off the power save option if you find it interferes with how you use your computer.
Click on the "Start" button at the lower left corner of the screen. Select "Control Panel" to open a new window.
Double-click on the icon labeled "System" to launch a separate window. Click on the tab in the new window labeled "Hardware."
Select the button labeled "Device Manager," then click on the plus sign icon next to "Universal Serial Bus Controllers." Right-click on the first "USB Root Hub" icon, and click on "Properties" in the menu that appears.
Click on the tab labeled "Power Management." Click on the box next to "Allow the Computer to Turn off This Device to Save Power" so that no check mark appears in it, then click on the "Ok" button at the bottom of the window.
Right-click on each of the other "USB Root Hub" icons, and follow the same steps to change the power save settings.