Windows Update

Follow this link for instructions on downloading the updates manually.

http://www.xp-erience.org/sections.php?op=viewarticle&artid=108

It was written for XP, but applies to most versions of windows.

There are a few updates that will not download this way, but most will.

You can either post the updates on the newtwork, or burn them onto a CD.
Then you can either go to each machine, or write a utility to install the updates.

You haven't stated which version of NAV you are using (or even frankly that you are using Norton's)... but yes, you can do this. Just setup the server with the virus definitions, and setup your client computers to access the server definitions.
A client computer with NAV CE (corporate edition) would be set to use NAV --> Live Update --> Connect via Network (instead of Internet)-->

There are certain things that need to be done on the server side too. You need to set your NAV CE network set up to use the Virus Definitions Transport Method (VDTM).

Go here to look up specific instructions on Norton's AV programs:

http://search.symantec.com/custom/us/techsupp/enterprise/kb/query.html

You won't get all of the updates this way, but you can go to Microsoft's Download page
http://www.microsoft.com/downloads/search.asp?

Select the version of Windows 2000 that you want updates for, select Windows 2000 as the OS, select all downloads, and your choice of sort by title or date. (I prefer date, that way I can note the order to install updates, and skip ones that have been replaced by newer updates)

There are 191 files listed.

Download the updates that are applicable to your systems. (I aslo create text files to describe what each update is for future reference) Burn them onto a CD, or store them in a network folder.

You might also want to download updates for any common applications that you use.

Then, install the appropriate updates on each PC.
I have seen (but have never used) programs to automate the process somewhat.

In my experiances with W9X, there are going to be a few updates that are only available through Windows update. If these are critical to your needs, you will still need to install them from Windows Update.