It could be the hard drive failing or it could be something that happened to me.
My tower was running at a glacial pace. I took it in. They checked it out and it ran fine. I brought it home. The ice age returned. Took it back. They showed it to me and it was running great. Took it back home. Mammoths began to die.
I had a stupid idea. What if it were the power strip? Changed the power strip. The tower ran great.
So try plugging it in somewhere else with a different power strip. It can't hurt.
Wow, that is amazing. TY.