This is not a malware issue - I've been to malware forums and my computer scans clean with a multitude of malware-detection services. I believe it's a registry/permissions/policies settings issue at this point.
I recently cleaned out some viruses and Trojans from my Windows 2000 machine, and now find my desktop wallpaper locked up. Certain other changes have taken place as well - such as the removal of my PopUpCop IE toolbar button, and toolbar lockup - upon reinstall of PopUpCop, I'm not allowed to have it add its toolbar button to my IE browser.
When I right-click on the desktop to Active Desktop/Customize My Desktop/Display Properties/Background, all image file choices are grayed out, and the wallpaper is locked to the last choice - an IE icon with the word "desktop". I've heard about "desktop.html" and did in fact find the registry setting:
HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\System Wallpaper REG_SZ C:\WINDOWS\desktop.html
... but there is no such file "desktop.html" on my machine.
By the way - replacing "desktop.html" with an image file in the above registry line causes the image file to appear during boot-up - but it disappears when the icons appear on the desktop.
I've also become familiar with registry settings such as NoChangingWallpaper. It seems to be in normal (not disabled) setting:
HKCU\Software\Microsoft\Windows\CurrentVersion\Policies\ActiveDesktop\NoChangingWallpaper = 0
What I'm totally unfamiliar with is how to set W2K "permission" and "policy" settings. I know some companies like to have their workstation monitors display their company logo, so they lock out their employees' access to wallpaper customization. I wonder if that's what's happened to my settings?
So I'm wondering how to recover the original settings/operation of the desktop wallpaper and IE Toolbar customization options?
Note: Prior to all this happening, I created a set of W2K boot-up floppies, and I have the original W2K CD. I tried booting up from the floppies but they seem to want to do a re-install and not a boot-up, so I did not proceed.
Thanks for any help!