vpn connection worked xp does not vista

I connect to two remote Windows 2000 servers using VPN. In XP, these both worked. I upgraded to Vista, now one works, the other does not (Error: 800). I have another XP machine and both VPNs still work on this machine, so I know the server is good. I have tried every setting but cannot get this second connection to work. What else can I try?

I connect to two remote Windows 2000 servers using VPN. In XP, these both worked. I upgraded to Vista, now one works, the other does not (Error: 800). I have another XP machine and both VPNs still work on this machine, so I know the server is good. I have tried every setting but cannot get this second connection to work. What else can I try?