Hidden devices

When you unplug a device from your computer, Windows will remember it!

This can get annoying, cause device names to contain "#6" etc... To show hidden devices in device manager try the following:

1. Click Start, click Run, type cmd.exe, and then press ENTER.
2. Type set devmgr_show_nonpresent_devices=1, and then press ENTER.
3. Type start "" DEVMGMT.MSC, and then press ENTER.
4. Click View, and then click Show Hidden Devices.

Source: http://support.microsoft.com/kb/269155