Question : RASMAN failing on client connection to server

I have a Windows 2003 server box with 5 clients connected all running XP.  Server runs DHCP, DNS, File sharing has been setup, even to the point of everyone permissions full control.  After a while the clients RASMAN (Remote Access Manager) fails and they are unable to map to a network drive.  I can go into cmd and ping the IP address & name of the server not a problem, just not look at the server in network connections, thus no mapped drives.  At first I thought it was an update of anti-virus software, but that has been removed and its still occurring.  After I restart the entire network a couple of times it comes back, assistance needed.

Answer : RASMAN failing on client connection to server

Hmmm...Looks like a job for WINSOCK :D...Ok.. It seems (assumption) WINSOCK or TCP stack, are corrupt. Please try this on your Server. Reset the WINSOCK and TCP Stack on your Server since the problem started after you installed Antivirus Update. You can use the Netsh Command to do that. Since the Server is a DC as well, the first reboot after the reset will take some time...Infact quite some time...but it should not be a problem..Server would probably get stuck on preparing Network Connections etc. Go and take a break at this point cause the Server will take its own sweet time to bootup. Once, it is up, Login and set the IPs again. Also, I have also seen this behaviour under a Virus attack. Viruses are known to flood the Network choking everything which relies on it. Are you sure, your machines are 'Virus-Free'?