I have a Mid 2007 iMac which I just recently decided to upgrade its OS to El Capitan. I download the software from the App Store then created a bootable USB drive to do a clean install. Well my iMac now crashes A LOT!! I ordered 4GB of RAM because my iMac came stock with 2GB and a 50% more RAM won't hurt but these are the current specs of my iMac.... iMac (24-inch, Mid 2007) 2.8 GHz Intel Core 2 Duo 2 GB 667 MHz DDR2 SDRAM ATI Radeon HD 2600 Pro 256 MB The question is what can be causing the computer to crash so much. Everything is find then it freezes up and after a few seconds it reboots. Is there a diagnostic I can run to find whats causing it to crash?