1. Have Winphone developer tools installed. Download is here (iso) - url :
([Only registered and activated users can see links. ]
2. Connect Phone via USB
3. Wait till zune starts and sync completes
4. Verify that zune is not in a guest relationship
5. open a command prompt, type netstat -a to confirm that port 443 is not being used
6. open an admin command prompt, navigate to c:\windows\system32\drivers\etc\ then type notepad hosts and delete any references to windowsphone developer services
7. go to the settings on the phone and turn airplane mode on (so that the phone is forced to use internet via zune)
8. While the phone is still on the settings page, run Chevron with admin privileges

Attention: if port 443 is used (see on your list) stop IIS or exit Skype program

best regard

source(member sushovande) :[Only registered and activated users can see links. ]