You can download winrar for free and open the file but we'll add a zip file for future downloads. Let me know if this solved the issue.
can I download the zip file later with the same purchase I made here?
I will probably try it later, with the winrar I mean. I believe even my brother who does this kind of stuff more often was suprised what was going on. However I suppose that is the correct file then? i think I explained it elsewhere too.