factory reset

[Powderfinger1]

I have been trying to do a complete 'factory reset' on a 2008 MacBook which originally came with OS X Snow Leopard - in order to pass it on to a new user. I had eventually upgraded to El Capitan & replaced the HDD with an SSD. I have successfully followed instructions to erase the disk & re-installed Snow Leopard, then moved on up to El Capitan, using my Apple id/credentials to sign in & download/install. I understand that I should be able to roll back via 'recovery mode' to a fresh install of El Capitan with none of my personal details but each time I try to achieve this I encounter problems at the macOS utilities stage. I get a message showing the hard drive & an exclamation mark & cannot go any further. I have noticed that when in disk utilities there are 4 entries (as shown in the attached photos). I understand that I should be erasing the actual disk which is the very first entry & not the indented one – or the lower ones. However in this view on another Mac I use, it only shows the actual SSD & then indented is 'MacOS'. Any help would be very welcome as I have now tried this several times with no success. I must be doing something wrong but not sure what, yet! Thanks in advance.

 

[ferrarr]

In Disk Utility, make sure you have enabled the option to Show all devices in the View menu.

 

[MacInWin]

I cannot make out anything from your images as they are too small and when I blow them up they get too fuzzy to read. However, you cannot format the drive from which you are booted. You either have to boot to Recovery Mode, or boot from an external drive.

Here is a link to the Apple directions on what to do to prep a machine for transfer:

https://support.apple.com/en-us/HT201065

and

Use Disk Utility to erase an Intel-based Mac - Apple Support

How to erase (format) the built-in startup disk of an Intel-based Mac.

support.apple.com