@SamTheGreat25 You wouldn't void the warranty by changing the thermal post, however, HP does not recommend doing the same, you could instead perform the below steps to reduce the overheating, please follow the below steps to resolve the issue:
Here's how you change windows settings to reduce visual effects:
Go to Start Menu > click on Settings.
Type performance > choose to Adjust the appearance and performance of Windows.
In the new window, go to the Visual Effects and select Adjust for best performance.
click Apply and Ok...this should do the trick.
I must let you know that its normal for any PC to heat up to an extent, and with a CPU such as the one you have, there's nothing to worry about, for details on why you don't need to worry: Click here to go through the CPU specifications, look under Tjunction of the CPU, it supports up to 100°C.
P.S: Welcome to HP Community 😉
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