See attached. I've tried to re-download the installer several times. My machine meets the minimum spec (I believe) and have sufficient space on the hard drives.
Any info greatly received..
Many thanks
James 
Hi James,
This is an issue with Windows and not with the Epic Games Launcher itself.
I'd recommend checking deeper the installer logs to find out what the exact error is.
Perhaps you could contact the folks from the store support here: https://www.epicgames.com/help/en-US/contact-us
Cheers,
Francesco