Why is the local computer not pinged from under RDP via OpenVpn?

Question

openvpn

3 computers win xp sp3, workgroup.
On two, if you connect to RDP win server 2008 via openVpn, the ping to the network card does not go to the computer (not a TAP adapter, but a wifi network card)
on the 3rd computer it pings perfectly.
The firewall is disabled everywhere, from antiviruses only essentials.
All this business is necessary for the operation of printers, tk. on the server, their connection with RDP is apparently disabled.
Tell me which way to dig.

Answer 1

Put Wireshark on the server and see how the packets go, it is possible that there are no routes on vpn clients

Answer 2

Towards routing

Answer 3

Check Network Level Authentication