So, there are MANY things that can cause stuttering, and most of them are not the CPU.
For one thing, I'd make damn sure you turn off system Restore for ALL drives. Restore images rarely work right once something happens to corrupt the system anyhow, nor does it work AT ALL if the drive is at fault. Mostly it just takes up valuable resources and a lot of them, and at very inopportune times. Last thing you need is the system trying to create or backup a restore image in the middle of a game. Turn it off. Use something like Acronis true image or Macrium reflect to create an image you can restore from and refresh the image periodically.
Or, simply do nothing and just do a clean install anytime something needs to be seriously addressed. Either way works so long as you turn off system restore and don't allow Windows to determine when and how backup images are created as it typically tends to do it OFTEN.
Two, do the GPU card clean install like I said. Driver issues are a common cause of stutters or any kind of gaming performance issues. They can also affect non-gaming behavior because the GPU card is being used under a variety of conditions, not just when gaming.
Three, make sure you have the latest BIOS version installed. This is the #1 problem we see when people are having unexplainable issues. If there is a newer motherboard bios version available, install it.
Update, manually, every driver used by your unit. The CPU chipset drivers, the sound adapter drivers, the iGPU drivers if your system has an iGPU, LAN drivers, WIFI drivers. All of these should be available on your laptops product page and you need to make sure you have the latest ones installed, but do it AFTER you have updated the bios if there is a newer bios version available.
Finally, download either Seatools for windows or WD lifeguard tools and check the drives, all of them if there is more than one, for problems. Run the Short drive self test (DST) and the Long generic test. Run it on all drives. The long generic will take a good amount of time.
Go download Memtest86 from Passmark software. Create bootable media and then boot to that media. Run the four full passes to make sure that your memory (RAM) is ok.