@HelenaFarr
We're not allowed to provide any official reading on warranty terms -- but in general, if the laptop case has screws or access ports, and you open and close it without causing any damage, then that typically does not void any warranty. But if the case is sealed and you pry it open, that leaves traces of what you did and probably DOES void the warranty.
But ... for an official reading on this, you have to contact HP Customer Support.
HP contact info: https://support.hp.com/us-en/contact-hp?openCLC=true
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