I'm going to start by providing all of the basics.
- Computer Group "A" (Any Windows 7 PC, all running Professional), Computer Group "B" (Any Windows XP PC), and Computer Group "C" (Any Windows Vista PC) are all connected to the Internet and are on the same subnet.
- All computers from group B can ping all computers from group C, and vice versa. They also can communicate through windows file sharing with absolutely no problem.
- All computers from Group A absolutely will not see group B in the network list, and group A computers will not ping group B computers by host name. However, if I type in a known IP address for a computer in group B, this works fine. This same thing happens in reverse, (B to A).
- I have network discovery turned on for the Windows 7 machines.
- I have file and printer sharing turned on for the Windows 7 machines.
- I have enabled sharing for devices that use 40 or 56 bit encryption on the Windows 7 machines.
- I have tried turning off password protected sharing on the Windows 7 machines.
- I have also enabled "Use user accounts and passwords to connect to other computers."
- On the XP machines, I have disabled Simple File Sharing.
- I have tried clearing DNS caches and ARP tables.
- I have tried using nslookup to find a machine, to no avail.
- I have disabled all Windows and 3rd party firewalls on both groups.
My Computer
- OS
- Windows 7 64 bit