Hello JRU2002,
Here are the system requirement for avast! 6:
Operating Systems SupportedWindows 7 (any Edition, 32-bit or 64-bit)
Windows Vista (any Edition excl. Starter Edition, 32-bit or 64-bit)
Windows XP Service Pack 2 or higher (any Edition, 32-bit or 64-bit)
Microsoft Windows 2000 Professional Service Pack 4
Your machine as you can see, is at the bottom of this supported ladder provided that you'veinstalled SP4.
I also know that Zone Alarm can cause a conflict.
If your system is up-to-date, I'd try eliminating ZA from the mix and see if that makes a difference.
There are many other Free Firewalls available.
(PCTools, offers a free one which is easy to use.)
Hope that helps.
I am running a Windows 2000 machine in dual boot configuration with Windows 95. About once each week or two I will get Avast refusing to start or failing to update until I log in as an administrator and update it from the add or remove programs section of the control panel. Every month or two it gets so bad it has to be re-installed. I also run Super Antispyware and Malware Bytes along with Zone Alarm Version 7. Computer accesses the internet through a router. Is there some Permission that needs to be changed that will avoid this or is it just Windows 2000 feeling it's age?

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