Hi,
Sometime you may require a PFX file ( SSL ) for Windows Server IIS. Go to below link and select options
Form ===> Standard PEM
To ===> PFX / PKCS#12
Provide all SSL files ( CRT , PRIVATE KEY & Intermediate Certificates ) , it will convert to PFX . Now your PFX file will be have all required SSL. Note PFX password which is required to install PFX.
https://www.sslshopper.com/ssl-converter.html