Make sure that you have build-ca.bat in easy-rsa catalog.
Otherwise try running following command(content of build-ca)
openssl req -days 3650 -nodes -new -x509 -keyout %KEY_DIR%\ca.key -out %KEY_DIR%\ca.crt -config %KEY_CONFIG%
Also 2.1.4. is outdated, and you will encounter errors on Win7. I'd recommend you to use 2.2.2.