Right you need to know the name of the Windows computer to do this.
Open Finder on the Mac. On the menu bar at the top, click go, click connect to server.
In the server address box type....
smb://computername/c$
Replace computername with the name of your computer. It will need a Windows administrator username and password.
I should have asked what the c stood for, my relevant drive is D, so it connected with D inserted vice C, still haven't managed to transfer anything, but at least I can now see the PC on the Mac. Thanks very much for the help.