I recently re-installed my windows and had to remove the old adb in order to run the application on my mobile device. My application uses google maps api v2 but now I can't see the map, only the zoom buttons. Do I need to get a new api key?
Your previous API key was linked to the debug key in you debug keystore located at:
C:\Users\<username>\.android\debug.keystore
If you've wiped out that keystore by re-installing ADB then you need to get a new API key for that new debug key.