Moving a website from unix to Windows?  Well I guess apache runs on Windows too but whatever.  Here’s the command you’ll need to build a PKCS12 format SSL certificate file that you can import into Microsoft IIS using OpenSSL from the command line:

openssl pkcs12 -export -out exported.pfx -inkey import.key -in import.crt -certfile import.CA

The four variables are of course:

• exported.pfx – the name of the resulting PKCS12 export file for import into IIS
• import.key – the current private key file from the apache server
• import.crt – the current public certificate file from the apache server
• import.CA – the current intermediate certificate file from the relevant certificate authority