====== 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"
<code>
Variable name: devmgr_show_nonpresent_devices
Value: 1
</code>
Click "Ok"

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