Seeing "ghosts" in Win 2000
"Ghosted" devices in Windows 2000 are hardware devices (usually non-Plug and Play) that, while not installed or running, nevertheless have drivers or Hardware Manager entries present for them. They may be devices that were removed or stopped functioning for some reason.
Ghosted devices can cause a host of problems. For instance, I've found that ghosted devices can sometimes cause Windows Update to detect and download unneeded drivers. The only way to remove ghosted devices used to be to boot into Safe Mode and delete them from the Device Manager there.
Thankfully, there is a way to show ghosted devices in the Device Manager without having to boot into Safe Mode. To do this, open a command prompt and type the following commands (or create a batch file with these commands and run it):
You can then right-click on any ghosted devices listed and delete them.
The "devmgr_show_nonpresent_devices" environment variable tells the Device Manager to show ghosted devices, but it is reset every time the Device Manager is closed. Therefore it needs to be manually reset every time you run Device Manager if you want ghosted devices to be visible.
Serdar Yegulalp is the editor of the Windows 2000 Power Users Newsletter.