How do I upgrade to El Capitan when the App Store isn't displaying it as available?

Before trying the installation again open Disk Utility which is in your Applications/ Utilities folder and run Verify Disk, if it picks up problems then you will need to restart to your Recovery Disk, (Restart holding down Command- R) and run Repair Disk from Disk Utility there. you could also try restarting your Mac inn See Mode and trying the installation from there, Use safe mode to isolate issues with your Mac - Apple Support

How to upgrade to OS X El Capitan - Apple Support

HI there...did this work for you? How did you do it?

I went to the link and it brought up a download 10.11.6 which I had already downloaded and my computer lion 10.7.5 (2011) is saying I need El Capitan 10.11 which seems to NOT be available.

Can or did Apple help here?

Frustrating as I have a perfectly good machine that I cannot nor AFFORD to upgrade.

Cheers,

Jan

This didn't solve my problem.

Please see my message in reply to macmomma2011.

I need 10.11 El Capitan for my 10.7.5 lion (2011)

This link downloads El Capitan 10.11.6 which I have already downloaded and my computer will not recognise it, saying I need El Capitan 10.11. NOwhere can I find El Capitan 10.11

HEEELP!!! Please!

Cheers,

Jan

The link I posted will take you to the App Store where you can download the full El Capitan installer (approx 6GBs) this will install the latest and last version 10.11.6. it sounds like you had previously downloaded an 10.11.6 update, which you need an earlier version of 10.11 installed before you can install the update. Just follow my link and download the full installer, this gets downloaded to your Applications folder, make a copy of it before going ahead with the install, keep the copy safe on an external drive as the one in the Applications folder self deletes after the installation has completed. It is handy to have the copy in case you need to re install it and saves having to download it again.

Hello...I'm in trouble!

First off thank you for advice and the download went well...until the installation.

Got to about 2/3rds of the way through and then a total white screen.

I have read up on other people who have gone through this.

I have tried SMC reset, have tried the hold down Command-Option-P-R...this time I came up with the apple logo and the bar running for the installation but only went about half way, then a coloured line appeared and went to white screen again.

Can you please help me? I am elderly and really not up with mod tech as such so explanation in easy terms would be helpful. Luckily I have an older mac to go on with at the moment.

Cheers,

Jan

Is the installer still in your Applications folder? If so try running it again either in the Safe Mode as suggested, or try installing in another admin user account.