Intel

Hard disk drives are many orders of magnitude slower than solid state drives.

Back in the day, before we had SSDs, this is how a lot of things worked. We would wait a long time for programs to open, and the operating system would sometimes hang (long enough that it appeared to be crashing) when switching between workloads. It was a slow and painful experience.

If you're doing the majority if you work off the HDD, it's going to be very, very slow. You can use the HDD for data storage, like backing up pictures, movies, music, etc. and you can even use it for some older games, but you should absolutely be running any modern version of Windows off an SSD at this point.

There could be something else wrong, but I feel pretty confident that you're simply underestimating how slow HDDs are.

From what you've said elsewhere it likely is your HDD but it's still good to take a look at your thermals. In HWInfo click the 'Sensors' button. It'll bring up a fairly long list of different readings covering power usage, utilization, temperatures, and more. Scroll down until you see your CPU and Core temperatures. The 12th gen Intel CPUs have a max temperature rating of 100C and will cut power and clock speeds if that ceiling is being hit. If you see any cores bouncing off that number (or close to it) when under load you have a cooling problem. It should usually be much lower than that though. Depending on your ambient temperature, case, and cooling solution it could range anywhere from 25C to 50C at idle. With any minimally decent cooling setup and while under heavy load 80-90C can be considered normal but a good cooler will usually keep you under 80C, sometimes significantly.