How do I connect to a Windows 7 File System from Mountain Lion

While we all have MacBooks in this forum most of us don’t run Mountain Lion. There's a Mountain Lion Support Community where everybody has Mountain Lion. You should also post this question there to increase your chances of getting an answer. https://discussions.apple.com/community/mac_os/os_x_mountain_lion

I have Mountain Lion and I have been able to connect to a Windows laptop on my home network.

Go to 'Go' in Finder and select 'Connect to Server'. Put in the server address as smb://[ip address] / [server machine name]

You will find the ip address by running 'ipconfig' in the CMD application on your Windows 7 machine. You will find the server name also in Windows under System in Control Panel. Good luck - it works but it is temperamental sometimes I have found and reboots on either machine often help !!!!