The connection automatically chooses a network adapter when installed. Choose one in the properties page for the connection.
I encountered this problem after I Installed VMware. VMware installed its own network adapters and the Routing and Remote Access service was set to randomly pick a LAN interface to use at startup (on the Network Selection page, "Allow RAS to select Adapter" was selected). Changing the adapter from "Allow RAS to select Adapter" to "Local Area Connection" (the connection that RAS should use) helped me to overcome this problem.
If you are using a MultiTech MT2834 modem, then see ME128976
Check if RRAS has IP Addresses available from its DHCP server.
Sometimes the problem can be that the DHCP is trying to give to a remote access client an IP address that is currently in use. This causes a conflict.
In order to fix the problem I changed the adapter on the IP tab located in the server properties in Routing and Remote Access Manager. This worked in my case.
From newsgroups posts, the link below proved to be the fix for this problem.