I cannot connect to a machine with a Windows 7 64bit operating system using Windows NT Security setting.

I have 2 other machines running Windows 7 32bit and they can connect just fine. If I change the security setting to use Radmin Security instead of Windows NT Security on the machine I'm trying to connect to, then the Windows 7 64bit machine can connect. My other 2 machines can connect with the same username and password through Windows NT Security and Radmin Security.

I've tryed turning off the Windows 7 firewall and LAN firewall, but still experience the same results. This machine dosnt have any other type of anti-virus or malware software that contain other firewalls.

I would have thought maybe it was a problem with v3.4 connecting to v3.0 (which is what the machine I'm trying to connect to has), but my other 2 machines use v3.4 as well. I've had a friend who uses v3.4 connect using the username and password from his Windows XP 32bit machine and he can connect just fine.

I've tryed multiple machines, from multiple locations (offsite and onsite) and the only machine that has this issue is the Windows 7 64bit machine.

Why it connects ok through Radmin Security, but not Windows NT Security? I do not know. Any ideas/help would be appreciated.