IIS 10.0 Detailed Error - 500.0 - Internal Server Error
HTTP Error 500.0 - Internal Server Error
php-cgi.exe - The FastCGI process exited unexpectedly
This happens when you do not have the correct VC++ redistributable installed.
You can check which version VC you need by looking at the downloadable section on php.net, for example:
VS16 corresponds to Visual Studio 2019,
So you will need to download the vc_redist package from Microsoft corresponding to your version and Architecture.