Recently upgraded to Android Studio from 2.2.3 to 2., running on Win10
Emulator stopped working since then. Tried installing other images(25 rev 4)/upgrading for AVD
I solved by modifying my configuration on AVD.
1) Go to the AVD Manager
2) Click "Edit this AVD" Button (the pencil icon).
I had no device selected and it showed an error message that I need to select a device for the AVD to work. Once I did that and saved my emulator worked.