Hi there. NEWT currently uses basic Windows ports and protocols. So you'd at least want 137 UDP, 139 and/or 445 TCP open. You also want the remote PC to be pingable. If we're talking Windows Firewall, you should just be able to enable the "File & Printer Sharing" exception to enable those ports. In addition, to get a full scan, you'll need ADMIN$ share access. Those are the only requirements.
So if you can get to the remote PC using "\\PCName" or "\\IPAddress" from Windows Explorer, that's the first step. Then if you can get to "\\PCName (or IP)\ADMIN$", you should be able to get a full scan.