The ARP table keeps track of the physical (MAC) addresses that are associated with IP addresses. Looking at your information, I can see that there is no entry for 192.168.1.139 in the client’s table and no entry for 192.168.1.101 in the server’s table. This means that what is most likely happening is the client is unable to resolve the “SERVER” name into an IP address.
Next thing, perform an “ipconfig /all” on each machine and see what it says. Also, just a random idea, try disabling IPv6 on WHS under the Network properties and see what happens.
