I setup my win2003 server as a VPN server and I can connect to it in client side. But I can't access Internet in client even as administrator. I read related questions and as they suggested, i've unchecked “Use default gateway on remote network.” on client machine. But It still said I have no right to access internet. What shall I do?
What are you using on the server - ISA, straight RRAS or something else? What is the VPN config like - PPTP etc?
Where is the client connecting from? Can you paste a copy of 'route print' from the command line of the client? The fact that you unticked that box should mean that the default gateway should be that of your local Internet connection (did you reconnect after this?) - if it doesn't work it suggests a routing problem of sorts.
Can the server access the Internet normally?
Sadly your question lacks detail which is why is has been down-voted.