Hi, I am currently having problems with a Windows 2003 server R2 (SP1). We manage the server remotely therefore diagnosing the problem (especially network related) isn't straight forward. We use RDC to logon onto the servers remotely. This morning the server appeared to go down, there are no outstanding hardware related problems, in fact the server is almost brand new. It was only brought into service in approx 1 month ago with no problems up to this point. The server is setup as the primary domain controller. It is also configured as a DHCP and DNS server (another server is the primary DHCP server). We monitor the server using CA unicenter and were first alerted to the server via the 2D map (server icon went red). At this point we tried to logon to the server (via RDC) which failed, in fact we couldn't even ping the server. We contacted the onsite ops team who advised the server is ON, normal harddisk and network light activity, and the server was sat at the logon prompt (as expected). We had to reboot the server, after logging back on remotely the only errors in the event log (repeated every 5min) around the time of the failure is: Source: Userenv Cateogry: none EventID: 1054 Description: Windows cannot obtain the domain controller name for your computer network. (An unexpected network error occurred. ). Group Policy processing aborted. For more information, see Help and Support Center at http://go.microsoft.com/fwlink/events.asp. I'm relatively new to investigating server problems, is there a good place to start looking into this issue? I wasn't sure whether this post (here) is the same issue (no reports of being unable to ping the server). Any help would be greatly appreciated, this is a bit of a learning curve for me. Thanks