I wouldn't start completely over. I was thinking just uninstall and reinstall the server. If the server won't start after the base install there is another problem. You might try installing the server in evaluation mode to prove that the base service does work. If that works, uninstall the server and reinstall with the license info and registration. When I say server I mean just the server, not the Web Extension or anything else.
There shouldn't be anying left in the registry that would cause grief. The server tries to avoid registry stuff since it has to run on linux and windows.
I'm not an expert with the license manager so I'm just using my understanding of the server install to debug this. I believe there was another post here regarding this that eventually the user was successful. I will try to find that.
I'm assuming the license manager is on another machine and you can ping that IP address from a dos prompt on your server mahcine?
Dave