I have read this topic http://serverfault.com/questions/67888/whats-involved-getting-domain-name-pointed-at-my-dedicated-server-win2008
but it's not precise enough for me.
At my registrar I have
A Records
Name (ex. www)
TTL (ex. 3600)
IPv4 Address (ex. 192.168.1.1)
When I tried to add www and the IP address of my own server it says error processing the request, why ?