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.
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!