Below is a brief example of how to use OpenSSL on Windows to convert certificates from one format to another. I have personally found this useful for converting PFX certificates to PEM format for use on LoadBalancer.org devices.
If you don’t have OpenSSL for Windows installed, head over to http://www.openssl.org/related/binaries.html where you will find a link to http://slproweb.com/products/Win32OpenSSL.html for the installer.
Converting a PFX to PEM format example. Note you will be prompted to provide the certificate password.