Go to Start> Programs> Windows Development Tools> Phone and run the application deployment
Make sure the goal is to "Windows Phone 7 Device"
Go to the XAP. You are loading.
Connect your phone, wait for Zune to sync. Make sure he is not invited.
Unlock the phone and keep you awake. Click on "Deploy", and the application of load (not too fast, and will appear in the list of applications without having to reboot when done). If not, the commission of a soft reset and try again.
Note: You must unlock the phone