Installation:
extract to a folder of your choice
Start a command prompt with administrator rights
(Search for cmd, open the command line on the desktop, right click and run as administrator)
navigate to the dll directory with the command line
type in the command line:
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regsvr32.exe epub_handler.dll
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The same can be done with the /u switch
It's a good idea to close all open Explorer windows before uninstalling
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regsvr32.exe /u epub_handler.dll
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System requirements Vista/Win7 or Win10

Translation
You can find it in a zip file by editing 'lang.ini'