Woodster wrote:It’s an iMac about 8 years old and I think the 500Gb drive is getting pretty full. Probably getting a new iMac next year so I want to back up everything manually so we can start afresh.
You don't need to do that because you connect the two Macs together and the new one asks if you want the data to be copied over.
What OS are you on? iPhoto disappeared with later versions and I know some people had difficulty with the migration over to Photos.
You do know about the Apple Refurb store ?
It could be that your drive is starting to fail. There is an excellent program called scannerz...free last time I looked. Basically it really puts your hard drive through its paces (in max diagnostic mode) and will (at the initial pass) give you a view regarding how its performing ...not 100% accurate, of course, because it is only a snapshot and a loose comparison against how similar drives should perform.
It's strength lies in the fact that it saves a detailed log regarding your drive and so if you run the test again in the future, it compares the two results and highlights if the performance has dropped.