PKCS 12

Problem

You need .pfx file to install https on website for Microsoft's or many other web servers.

If you have two separate files: certificate (.cer or pem) and private key (.crt) they need to be converted to P12 or PFX format.

Solution

You will need to use openssl.

 openssl pkcs12 -export -out domain.name.pfx -inkey domain.name.key -in domain.name.crt

The key file is just a text file with your private key in it.

If you have a root CA and intermediate certs, then include them as well using multiple -in params

 openssl pkcs12 -export -out domain.name.pfx -inkey domain.name.key -in domain.name.crt -in intermediate.crt -in rootca.crt

You can install openssl from here: openssl