Hi don
Are you able to ping the internal resources once you are connected using VPN client? have you tried the same with your friends pc as well ?
what about the reverse connection from the remote lan to the pc, are you able to ping the pc ip once its connected to the remote vpn.
what about the OS and AV installations in the pcs ? is there any specific FW/HIPS sw installed in any of these pcs?
regds