Show all connected and disconnected devices in control panel in Windows 7

Want to see all devices you ever connected and installed on your Windows box?

Open Control Panel > System Click on “Advance System Settings”, then on “Environment Variables” In “System Variables” section, click “New”

Variable name: devmgr_show_nonpresent_devices
Value: 1

Click “Ok”

Open Device Manager (Control Panel > System > Hardware > Device Manager) In “View” menu, click “Show Hidden Devices”