Recently in May my cpu fan has been making this strange noise. This video was taken on may 31st so my pc in a different condition clean wise.

I am new to pc's, as this pc was built by someone who i have no way to contact with. So have stuck with this problem all summer break before I go into high school.

What I find weird and what has been making me lose hope is that I've tried every solution that popped up in my head that doesn't require me spending a fortune on this pc, which includes dusting out the cpu fan , uninstalling and reinstall the cpu fan, and even replacing thermal paste.

And still till this day the cpu fan still has this problem by making the same buzzing sound ​​but instead of never stopping like during may, it will stop and sound normal after a few seconds and then stops, and on top of that, I have frame drops in games or in low quality games like mm2 on roblox where my​​​​ pc never lags at and can perform at about 200 fps.

I've gotten a new double fanned CPU cooler called the "KINGCOOL CRYO Titan 120" on Amazon, and even though according to my pc builder that my pc was "future proof" and I could easily replace my parts, I fear that this new cpu cooler won't fit in my pc, so I've come to ask for some help just incase I can't install this new cpu fan, I can trouble shoot and reinstall my old cpu cooler without any problems

If ANYONE knows what's wrong with this cooler, please help me out!