I was running Windows 98 SE for quite some time, and had installed a neat little utility called PopupRemover to squelch the scripting virus my PC had contracted. All this util does is intercept requests to launch popups in Internet Explorer and terminate them.
Anyhow, I didn't un-install this app before upgrading to Windows XP Home (ignoring the advice XP's install gave me about this app), and when the upgrade was completed my IE was totally crippled. The PopupRemover app was not shown as running, there was no icon in the system tray, and I couldn't locate the process either. I finally found that I had to un-register the PopupRemover DLL from the command prompt using "regsvr32 /u <dll name>". This finally alowed me to delete the dll (after a reboot) and be rid of this pesky non-XP friendly app. Hope this helps someone!
