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
It is probably your Skype giving you a hard time. Try configuring your Skype this way:
Tools -> Options -> Advanced -> Connection -> Unchecking the 'Use port 80...'
I had the same problem and it worked for me.