Answer 1: There are too many softwares installed on the computer, which leads to disk confusion and slow disk reading. (Solution) Reload the system. Answer 2: There is too much junk software in the system. Clean it regularly.
The hard drive is fine (unnecessary). If you can't do as I say, if you have friends in this field, ask him to check it for you. If you can't explain clearly, it's right here.