I had a hard time configuring this component, because the instructions are out of date (at least for Windows). Since version 0.12.3, the mingw package is no longer generated.
So, instead of following the first step of the installation instructions, follow this link to the last working version of wkhtmltopdf: https://github.com/wkhtmltopdf/wkhtmltopdf/releases/0.12.2.4/. Use this package to extract the needed files and upload them to the component.