I would like to do a final reply for all of those that have had this same problem. Crazybob and I finally realized what was causing the problem. It was not the actual login to the domain with the administrator password, which we could do with no problem, but it was being able to login to the local machine with the administrator password.
In other words, if you cannot get into the local machine as an administrator, then there is excellent chance that avast will not either. This is where I believe the error 1326 is coming from.
So do the following if this happens:
Login to the domain as administrator
In Control Panel open User Accounts (Users & Passwords for 2000)
Highlight the administrator account for the local machine, if it does not exist then add it (Be sure to put in the local PC name in where it ask for the domain name).
Click on Reset Password for the local machine
Reboot and have and login on the domain either as the user or administrator. It should now work!
One last note, if the above still does not work, go in locally as administrator and rename it. At this point it will definitely work. Please note that to use this as a final resource, whereas, the above should work.