Proper VPN installation

Use same vendor on both sides

it's a clear and sound procedure to set up a VPN IF you have xp os.

http://support.real-time.com/windows/vpn/windows_xp_vpn.html#setup

I managed to connect 2 networks with the same vendor appliances at each end. A tunnel opens up and I can ping IP addresses at the other end so I have had success. Another question: I tried the "Make a New Connection" in XP for VPN and it keeps trying to dial a VPN connection even though I picked the "Do not dial this connection" option. Both sites have cable. Any ideas? Also, does this method allow a user to access and execute programs remotely or is it just for file access?
Anyhow, thanks to all for the help.

As long as the VPN gateway that you are using is VPNC Certified, it should be no problem in the interoperability. You can either have gateway-to-gateway implementation using IPSec if you have multiple users behind the gateway sharing the tunnel. Or Host-to-gateway implemetation for mobile users where it can be IPSec (require IPSec client softeware) or L2TP by using your built-in VPN dialler in XP. Best practise is to use IPSec instead of L2TP or PPTP. Hope this helps.