Given Windows XP is being phased out just about everywhere, I’m not sure how useful this blog is anymore, but it’s possible it might also apply to the other flavors of Windows.
On Windows XP, Windows Vista and Probably Windows 7 you may see the error “can’t open config file /usr/local/ssl/openssl.cnf when running the openSSL executable. No big deal. The reason it can’t find the file is the environment variable OPENSSL_CONF is most likely not set, or is pointing to the wrong location.
The solution is simple. Open up a command prompt (also known in the old days as a MS DOS Prompt) and type the below statement:
set OPENSSL_CONF=c:\[PATH TO YOUR OPENSSL DIRECTORY]\bin\openssl.cfg
Replace the [PATH TO YOUR OPENSSL DIRECTORY] with the location of your openSSL install.
Note, that if you choose not to add this line to your environment variables, then you will need to run it each time you want to invoke the openSSL executable. Otherwise, you will get the same error again.