More information needed.
What "stuff" are you downloading and where are you getting it?
What are you using to unzip the files?
im using windows 7. im trying to follow that guide, but that guide is for windows 10. ..i cant seem to find follow that guide.Here is what you're looking for.
https://www.digitaltrends.com/computing/how-to-change-file-associations/
Go to the "Changing any and all" part of the article.