Show Hidden Devices (Windows)

There are a number of instances where devices that were once part of a system no longer show up, however nearly all of them result from the simple removal of hardware.

One would think that simply loading "Device Manager" and selecting "View" / "Show Hidden Devices" would be enough to view them, but alas no.

Thankfully the solution is really simple:

1. Open a command prompt
2. Type set devmgr_show_nonpresent_devices=1
3. Type devmgmt.msc
4. From within Device Manager, select "View" then "Show Hidden Devices"
5. Browse the various categories of device for any that are greyed out.  Right-click on them, and select "uninstall" 

[Note: Do not uninstall devices that you are unsure about.  This could leave your system in a non-working state, although Windows should automatically scan for and re-install any missing devices, if specific software is required, this is not always possible]