via VPN , I can’t see local PCs

Hi, there, here is my situation:
1.Window2003 server with 2 nics,
1 is 192.168.2.0 with internet GW 192.168.2.1,
another is 10.0.2.0 net and connect with a switch.
2. WinXp with a NIC on 10.0.2.0 on that switch

Winxp connected Win2k3 server with PPTP VPN, getting ip address in 192.168.2.0.
The problem is Winxp can surf and email, but can’t see any PCs in 192.168.2.0 net, even ping GW is n/a, what’s going on here?
any help will be appreciated.

alex