Officially, Python 3.9 and above are not supported on Windows 7 SP1 and Windows Server 2008 R2 SP1. Here, you can obtain unofficial Windows installers that bring back support for these older Windows ...
StaxRip 2.5.0 and later versions ship with portable VapourSynth R53 and Python 3.9.x. Since Python 3.9.x does not support Windows 7, you can't use VapourSynth on ...