I just installed Wampserver 2.1 on my windows 7 64bit computer and the icon that should turn green, turns orange, saying that the server is not ready.
The result is
I had this problem with an orange wamp due to that IIS and/or the Web Deployment Agent Service used when developing web applications in Visual Studio was blocking port 80. When I stopped these two services wamp started just fine with a beautiful green icon :)
Run these two commads from the commandline as administrator to stop the services
iisreset /stop
net stop msdepsvc