Windows 7 Networking issues in same workgroup

[arielrud]

I set up 4 different PCs. 1)running Windows 7 2)running Windows 7 3)running Windows XP 4)running Windows XP 64-bit

Now, I can access and login between PCs 1 & 2, I can access and login PCs 1 & 2 from PC 3.

Attempting to login to PC 1 from PC 4 fails but I can access and login PC 2.
I receive an error message "Access denied - error code 0x80070035" when attempting to login to PC 1 from PC 4 without receiving a login / password dialog.