If you a try to host a service in Windows Vista, you will receive an AddressAccessDeniedException. It is because of overly secured environment of the Windows Vista.
You will receive an error stating
HTTP could not register URL http://+:8000/. Your process does not have access rights to this namespace (see http://go.microsoft.com/fwlink/?LinkId=70353 for details).
You get this error because the owner of the http publishing is the built in administrator and you will not be running with administrator privileges.
You have to add the HTTP namespace to your user account. For that run the Command Prompt as an Administrator and run this command:
netsh http add urlacl url=http://+:8000/ user=DOMAIN\UserName
You can more details here
