Chosen Solution
All hard drives running at 100% usage for any program (mostly “system”) on new laptop. Hard drives continue to run slowly after being put back in working laptop. Unless it’s because of the bios it is a hardware problem not a software one.
Larger images from HDD killing laptop and slightly smaller images from Good laptop that has never harmed a HDD Edit The drive went back to normal after playing some games. Work fine on both laptops too. Edit The problem is back.
@just_terrible tell us exactly what you mean by 100%. Yes, a bad connector might do that but you said you had this before you changed the drive. Let us know why you changed the HDD. Was there any issues with the read or write access. Did you have trouble with your computer or was this just based on the 100% . Post some images of what the task manager displays with your question. Use this guide Adding images to an existing question for that. What version windows are you using since my task manager displays my disk activity in MB/sec?
