Have you followed the earlier instuctions to reset the keychain?
does the user "ROB" exist on the PC? (not rob or Rob)
and are you using the same password to logon as you did on the PC?
It would probably make life a lot easier if you also create a new user account on the Mac called ROB, with the same password
And are you sure the Windows workgroup is called "Workgroup" - on many versions of Windows the default is "Home"