LATE 2009 MACBOOK MEMORY UPGRADE INSTALL

I've tried doing the El Cap install from within OSX. I have a bench computer I can restore the account onto to do the photo work, but would actually like to give this computer back to the client upgraded. Fortunately I made a Time Machine backup before doing anything, and that restores just fine. I've tried formatting and deleting the drive and trying it with an empty drive. Just to be on the safe side, I reset it with the terminal command, but that didn't change the outcome. However, the system clock on this computer is correct.

I googled the error and every solution says it's about a system clock that needs to be reset with a terminal command. The error message I get is 'OSX could not be installed on your computer. However, the damned Mac refuses to upgrade to El Capitan. My recommendation was to take the old Mac, currently on 10.6.8, upgrade it as far as it can go (which is El Capitan, according to the interwebs), then download all the pictures from iCloud to the photos app, and then create a new Gmail account and upload all the photos (over 12,000 btw) to Google Photos. The photos on the phone are 'optimized', which means they really live in iCloud, and have to be downloaded to a computer to get them back. They are currently on the old Mac, or in her mother's iCloud account - her Apple ID is an old work email address. Client has her mother's old MacBook - Mom, an artist, has been diagnosed with Alzheimers and terminal cancer, and client want to make sure all her pictures from her iphone and her Mac are safely stored somewhere accessible to the family.

Late 2009 macbook memory upgrade