While working with WCF service on Windows Vista, I came across the following error, which I am sure everybody who have created the services on previous versions (Windows XP and likes) and trying to migrate their services to Windows Vista would have encountered.
The error occurs due to the new security settings in Windows Vista. Most people are no longer going to be running with Administrator privileges by default like they were doing on earlier platforms. This impacts your ability to run HTTP web services because listening at a particular HTTP address is a restricted operation. By default, every HTTP path is reserved for use by the system administrator. Your services will fail to start with an AddressAccessDeniedException if you aren't running the service from an elevated account. The account under which the Visual Studio and the debugger runs does not have the privilege (though the user account under which VS is runnig may be a part of Administrators group), and hence the error occurs. The plus sign in the URL just means that there's a wildcard being applied to the hostname.
To fix this problem, the owner of the HTTP namespace (built-in administrator) needs to delegate this ownership to the user account under which you are running your application (most of the times, it's the logged on user). To do this, start a command prompt using "Run as administrator" so that you have elevated privileges. Then, use netsh.exe to give some of the Administrator's HTTP namespace to your user account. You can look at the existing HTTP namespace delegations by using "netsh http show urlacl".
Now, use "netsh http add urlacl url=http://+:8000/ user=DOMAIN\UserName" to assign the HTTP namespace to required user account. You can get the syntax for all of these commands by running "netsh http" without any arguments. Note that I've matched the URL in this command to the URL that appeared in the error message. The wildcarding is important for getting the right reservation and you'll continue to be denied access if your reservation covers less than your service's attempted registration. Go back to Visual Studio and check that your service runs properly.