Can't boot after El Capitan Installation Partly installed El Capitan on my Mac Book Air and was unable to finish the installation due to time. Now when I go to log into my computer the home screen with my personal icon is white, and when I put in my password the screen fills with code.(black bars with white writing) Then an Apple Page comes up saying my computed wont start because of an error. That it needs to be restarted. Every time I restart it or shut it down the same thing happens. 

How can I fix it please?
Shut down your computer. Press the power button and before you hear the boot chime hold down the Command (Apple) key and R at the same time.
This will boot you into Recovery Mode. You should then be able to connect to your network and reinstall the operating system.