Fault with Install OSX Sierra

[ClareBell]

After a power failure I could not reinstall the OSX Capitan so had to restore from Time Machine. All went well but my 2010 Mac Book Pro is now running slow and refuses to run iPhoto. I would like to upgrade OS to Sierra but the Apple Store says I already have OS Sierra but I certainly do not! So can I download and install Sierra or High Sierra. I can't find these on App Store anywhere. Thank you..

 

[TonyAguila]

Try this Apple Support page:

How to download and install macOS - Apple Support

Download and install current or previous versions of the Mac operating system on compatible Mac computers.

support.apple.com

If you are able to download the installer, I suggest aborting the automatic installation at first, then make a copy of the installer file (in your Applications folder) to another location, and then restart the installation by launching the original file or simply rebooting. The installation will automatically restart. That way, you have an intact copy of the installer for future use.

 

[ClareBell]

Thanks Tony, yes I could move the file from the Applications folder to the desk top. However when the installer is run from either location I get the message "This copy of OS High Sierra Installer is damaged and cannot be used". So shoud I delete it and get the installer again? I also have trouble finding these in the App Store. I went to the support page you gave "How to get old versions of macOS" and got to the OS HIgh Sierra page but when I pressed "open" it gave the same message "This copy ... is damaged and cannot be used"? So I am realy puzzled as to what is happening. I could not see anywhere on the page where I could download a new installer only the [open] button which I gather runs the installer.

Thank you so much.

 

[TonyAguila]

If you didn’t notice, I wrote “copy,” not “move.” The original download should stay in the Applications folder. The copy is for future use. Anyway, I suggest downloading it again and allowing the automatic installation to proceed. You can always download it again in future.