Show Hidden Devices in Device Manager

This is a great from from the latest issue of the LangaList newsletter. If you aren’t a subscriber to either the free newsletter or the paid one, I would highly recommend you get moving!

Ghostbusting In Device Manager

Hi Fred, Really enjoy the newsletter. I searched the archives and didn’t see any mention of this, so thought I might actually have something to contribute.

Windows keeps a Device Manager entry for every piece of hardware that’s ever been recognized by the system, regardless of whether it is currently present in the machine or was even set up correctly in the first place. The “View Hidden Devices” option in Device Manager won’t show you these “residual” drivers. You can force it to show you everything by going to My Computer Properties, the Advanced tab, Environment Variables, and adding a new system variable with the name “DEVMGR_SHOW_NONPRESENT_DEVICES” and a value of 1. Now opening Device Manager and choosing “Show Hidden Devices” really will show you everything. Standard practice at the factory is to use a single image and just move it from model to model, letting it plug and play all the new hardware along the way. This leaves you with an impressive list of hardware still in the Device Manager, but no longer in the system. You also see this to a lesser degree when you restore a system from an image you created for backup purposes. These “residual” drivers can sometimes cause all kinds of weirdness and are best removed by right-clicking on their entry in the Device Manager and choosing “uninstall”.

This works on Windows 2000/XP (and I assume Server 2003, though I haven’t tried it). Anyone running a factory loaded Compaq or Dell will be amazed at the amount of junk left over from this process.

Best Regards, Jon Pickle

Thanks, Jon. Indeed, Windows has a thing about hanging on to ghost entries in Device Manager and also in the Registry. (This is one of the reasons why Registries inflate so much over time.) A little judicious ghostbusting lets your PC run cleaner and leaner!”