I installed Apple's latest security update last night, 7-24-2017. When restarting, my computer fails to boot to El Capitan and restarts once again. (It shows the apple logo with no progress bar and then restarts). I can follow step-by-step instructions, so if you can help, I will need the steps. Before the security update, everything was working fine. All previous updates worked flawlessly.
From what I have read, so far the only fix is to reinstall El Capitan. How would I go about doing that? I have a week-old backup on Time Machine. Is there a way to just reinstall Mac OSX from that without losing my more recent data? Or, I have the original El Capitan that I downloaded over a year ago from the app store (for my Hack mini build). To reinstall El Capitan, I would need step-by-step instructions as I am not a very tech savvy person.