Laptop slow death troubleshoot: Issue in HDD, Motherboard, Software, or other?

[AroundTheWorldHoes]

My Toshiba Satelitte P55-A5200 just turned on for it's last time a few days ago. Now when I try to boot, I get past the Toshiba screen to a black loading screen with a Throbber, and this is as far as I get. My hypothesis is the hard drive was damaged over time (as its performance has worsened the last month) and has now damaged boot files in the HDD.

History:
- Several month ago my computer had a virus which I'm pretty sure was removed
- After this, I fell walking up the stairs once and my backpack (which contained my laptop) made some contacts with the cement. I'm not sure if the laptop connected with the ground.
- Within the last few months, the device has run worse and worse: boot time has slowed, random processes would take much longer than expected, etc.
- I also experienced a unique issue where my computer would not run programs and the Task Manager showed the disk (HDD) running at 100%. I was unable to resolve whether this was a hardware or Windows 10 issue.

Some of these issues have just gotten worse until yesterday when the laptop gets stuck during booting.

I would appreciate any problem solvers out there to give their best shot to hypothesize the root cause of the issue.

Thanks

 

[BadActor]

Likely the HDD. They live a tough life in a laptop and dropping them, even if they don't directly hit a hard surface, still causes them to experience high G's. I would replace it with an inexpensive SSD and breathe a little more life into the laptop.