macos on old macbook air
Hi i have a late 2010 macbook air and am getting frustrated with things not working - i have yosemite - i have tried to download and install sierra and high sierra. sierra downloads, it is 5.1gb but says it needs 16mb space and then installs but no difference - i click the high sierra download - it launches app store but if you click download it says - "This copy of the Install macOS High Sierra application is damaged, and can‘t be used to install macOS."
can i install high sierra and if so where can i get it from?
thanks
MacBook Air