Microsoft Windows maintains the configuration (enumeration) information for every USB device that has ever been connected, unless you explicitly uninstalled the device before unplugging it. When a USB device is not physically connected to the computer, Windows does not normally display the device in Windows Device Manager. These USB devices are called non-present or phantom devices.
Windows Device Manager can be used to uninstall or change the properties of non-present USB devices after a session-specific variable has been set. This variable can be set in a command window in Windows 2000 and later. These commands must be Run as administrator in Windows 7, Vista or later.
- set DevMgr_show_NonPresent_Devices=1
These commands set the variable and open Windows Device Manager. In the Device Manager window, click the View menu and set the ‘Show hidden devices’ option.
Non-present devices appear with a ghosted icon. Right-click on the non-present device and select ‘Uninstall’ in the fly-out menu.
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