I installed Windows 2000 Advanced Server on a pentium IV 2.66 GHZ with 256MB of RAM, and a 40GB hard disk.
I installed DNS after I was sure that Windows 2000 A.S. is working properly, without any errors. It installed properly.
Then I setup a Domain Controller on this system, added users, and everything was OK.
After I added the first computer to the domain, the DC reported some errors with DNS. I checked Event Viewer regularly and understood that those errors related to autoupdating of forward lookup zones. Thus I put a message here in Experts Exchange, and learnt how to solve that problem. By now, no error messages apear in Event Viewer. But a big problem has happened:
From the moment I added computers to the domain, when I log off the DC and leave it for about 30min, and on the other side, users are logging in and off, my DC starts to be so slow. I usually log in on my DC within a 30 seconds period (maximum), but this way it takes at least 2 minutes. When I want to open Active Directory of Members and Computers, it takes some time, and when it is open, and I double click an item, the property page does not open. I can not close AD window thence, as it says "close all proprty pages before closing the window" while the propery page is not open yet.
When I restart this server, it will be OK for some 30min period, and after that, the problem happens again.
I am sure that no viruses infected this computer. As much as I understand, such problems relate to DNS problems, since the server repeats some lookup tasks and slows down, but I am sure that my DNS is working OK.
Any ideas? I need possible causes to be checked.
My other computers run Windows 2000 Professional.
Thanks in advance