It's time to "upgrade" to WinXP, since support for Win2KPro is running out. But I can't get ZoneAlarmSecuritySuite - ANY version - to install in Windows XP. Install always hangs at zquarantine.dll. Such a mis-install is a total disaster without a prompt system restore, (which I always did) no matter what the software is.
I made the mistake of first installing Avast antivirus with a basic ZoneAlarm free firewall, for better update speed. Avast's fast auto-update once conflicted with Windows Update, crashing system - with lost clusters. (I did a prompt restore.)
I have used several registry cleaners to remove virtually every trace of Avast and other uninstalled programs from my system and registry. I even use one registry cleaner program which, though it can be dangerous if misused, it can delete "no permission to delete" legacy registry entries. (Even "RegAssassin" fails.) But I dare not edit the registry in the local machine-system-control set-control-session manager-app compatibility-start menu-bit buckets branch, which contain long binary values which include traces of the otherwise thoroughly cleansed Avast anti-virus and other uninstalled software. Yet, when I run XP's Security Center, XP still somehow detects the presence of Avast.
From the other posts I see here, it looks as if I have no choice but to cold-reinstall Windows XP. Perhaps a critical file got corrupted with those lost clusters, System Restore notwithstanding. I'm consoled somewhat to see here that ZoneLabs Security Suite is usable on Apple OS computers.