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 the same error today. I changed the #listen from 80 to 86 and it still did not work.
I found this on the wampserver forum:
After this my icon finally turned green. However when I went to localhost it still said not found. This is because you need to append the new port you are using to localhost - ie localhost:86