From the drop-down menu, select Register Product .
Sometimes, particularly if you are using the "Express" edition or if the menu option is grayed out, you must change the key through the Windows Control Panel. how to enter product key in visual studio 2013
Below are the two main methods to enter your product key. From the drop-down menu, select Register Product
Click Apply . Visual Studio will validate the key. If successful, the status will change to "License: Product key applied." Method 2: Activating via a Signed-In Account From the drop-down menu