Since its been a year since the Windows 2000 release and everyone seems to have their own opinions about Windows 2000 after the first year, I decided to list my own discoveries and insights.
In April 2000 I started with Windows 2000 Server by upgrading our Primary Domain Controller from NT Service Pack 6 to Windows 2000 as well as added the second processor to our server. The installation appeared to go well but shortly after that we started getting weird errors and occasionally users were unable to access the server until I rebooted it. This led to me creating a new Window 2000 Domain Controller and converting it to the PDC emulator. Once that machine was up and running good I wiped out the original machine and rebuilt it from scratch. That machine is now running as our Terminal Server and hasn't had any lockups since I modified our Norton Antivirus install to not run autoprotect on all the Terminal Server sessions (There appears to be a memory problem running NAV Corp 7.0 on Windows 2000 Terminal Server).
August 2000 we converted our last NT 4.0 Domain Controller to Windows 2000 by doing a clean install. We also added the second processor to that machine at the time. This install involved replicating the Active Directory over our 128K Wide Area Network, which we were never able to get to work with NT4.0. It was a slow replication but we had the domain controller up and running before the users were back the next day with no problems. That server has been up and running both as a Domain Controller, File Server, and now also a Terminal Server.
Once the last NT4.0 Domain Controller was upgraded I converted our domain from mixed to native mode. This is the easiest step in the upgrade since all that is involved is the click of a button and it is done.
The best parts of the Windows 2000 AD in our situation are Sites, to allow our users to log on to the nearest controller (before that some users were logging out over our WAN links), Organizational units, to allow us to set up specific policies for all our branches and departments, and Group Policies, which is making my job administering the network much simpler.
The biggest problem I have is that our Antivirus will not run properly on our Terminal Server without a nightly reboot to free the memory. If anyone has solved this issue I would appreciate any help they can provide.
The biggest thing I can stress about server installation is to do a clean install wherever you can. Upgrade your PDC to Windows 2000 then add a new Domain Controller and make it the new PDC (turning the old PDC into a member server is probably the easiest) then rebuild the old server.
Also make sure to backup the old server first in case of any problems.
We started upgrading our workstations to Windows 2000 Professional during RC2 when I set up my own workstation. The first thing I had the released version of Windows 2000 installed on was our Sales Managers laptop so he could have better mobile support and be able to use a USB flashcard reader (for a digital camera). Again I made the mistake of doing an upgrade from NT4.0 which led to a clean reinstall when he started complaining about things not working. We did a number of upgrade installation that have come back and haunted us until we wiped the machine out and rebuilt it from scratch.
My first rule of Windows 2000 Deployment
If you can avoid upgrading the existing operating system do so at all costs.
We have installed about 80 of our 150 desktops to Windows 2000 and converted another 20 to Thin Clients over the last year with an almost perfect track record. Almost all of the problems we have encountered involve unsupported hardware or software.
My second rule of Windows 2000 Deployment
When you are doing a migration to Win2K Pro make darn sure your hardware is supported and test the software very well.
We had one program that works with Win2k Pro with no problem but as soon as we installed Service Pack 1 it stopped working, so also check before applying any service packs.
I believe Windows 2000 is probably the best Windows operating system released yet. It is very stable (I've rarely rebooted the servers, mainly because I am used to NT where I had a weekly scheduled reboot), Fairly easy to install using unattended installation or Sysprep/Ghost, user friendly, and powerful. The biggest downside is system requirements, though I am running it on an old IBM Thinkpad (Pentium 150, 80MB ram, and 2GB HardDrive) with far better results than I had with Windows 98.