A client gave us a MacBook Pro Mid 2009 that had some issues booting. The MacBook had El Capitan installed but it would not reinstall. After backing up the user files we then attempted to perform a recovery which attempted to restore the system to Yosemite, but that failed as well. Out of a last resort we had a copy of Snow Leopard v10.6.0 that we were able to use to reformat the drive and then install the OS. Here are the remaining steps we took to get the system retored to El Capitan.
It is important to remember that when installing any Mac OS that you don’t have any non-Apple peripherals connected such as a mouse or keyboard as these will often cause the install to fail.
We hope that this information is helpful. Please let us know how this has helped you or if you have additional questions. As always Firestone Technical Resources, Inc. is here to help with your computer support issues - "Providing personal service for your impersonal technology."