Use a Different PHP Version

[jayyenn]

I am following the rules in the XAMPP howto (/dashboard/docs/use-different-php-version.html) to run an older version of PHP.
My current setup is PHP 8.0.2 and I am trying to get 7.4 to work but Apache fails when I try start it in control panel.
I've tried obtaining the older php folder both from the php website and by downloading an older version of XAMPP.
Any help would be appreciated.