Why did the computer start to slow down?

Question

Windows

Hello.
A few days ago I ran into a problem, the computer began to slow down a lot in some tasks.
Programs began to hang (in particular the explorer)
Files are downloaded for a long time through chrome.
I also noticed that the speed of switching on and off fell by more than 10 times.
List of probable causes:
1. Cleaned the PC from large files using WinDirStat, including on the system partition.
2. Carried out various optimizations and cleanings in DISM ++ and Auslogics Boost Speed
​​3. Updated drivers via IOBIT Driver Booster and Auslogics Driver Updater
4. Also reconnected drives in the system unit and connected a drive that was previously disabled.
5. Connected the supposedly broken hard from the laptop for diagnostics.
List of disks:
1. SSD A Samsung 850 EVO 250GB disk that is less than 2 years old, and in fact it runs Windows 10 Pro with all the latest updates.
2. 2 HDDs Seagate Disks 500 and 2000 GB each (Quite old but no problems were noticed behind them)
Tell me what could be the matter?
UPD
Disconnected all drives except SSD, it seems that the flight is normal so far.
Checked it in CrystalDiskInfo
Here's what I got:

Picture

UPD # 2
With one drive (SSD) turned on, out of three problems, there are no more than an hour.
UPD #3
I connected both drives, the problem returned again, so the assumption was correct, it was the drives.
Here's what CrystalDiskInfo shows about both drives:

HDD Seagate 500GB

HDD Seagate 2000GB

UPD #4
I ran the disks through the SeaTools utility, it says that everything is ok ...
And who to believe?)

Here's what SeaTools says

UPD #5
Did a couple more tests, here's what I got:

WhySoSlow

WhySoSlow Analyze

LatencyMon

I did a couple more tests in SeaTools, and everyone says that everything is ok.
UPD #6
Today I continued the tests, and tried to disconnect one of the hard drives, namely the one with 500GB, the problem disappeared.
But if you believe the SMART data, then it is in better condition than 2000GB, but the system works stably with it.
In short, some kind of magic.
The disk seems to be broken in fact, but not broken according to the tests.

Answer 1

Fuck all of these and never use them:
* IOBIT Driver Booster
* Auslogics Driver Updater
* DISM++
* Auslogics Boost Speed

Answer 2

Most likely some application is to blame. Remove the last installed software one by one and watch the changes. At least the conductor and the on / off speed is suitable here.

Answer 3

Most likely the system was corrupted.
When using malicious software like Auslogics Boost Speed, and IOBIT Driver Booster and DISM ++, this should be so.
The treatment is simple - roll back to the checkpoint and work on.

Answer 4

What kind of system do you have, what OS is installed and remove it cleanly, what is recommended to you

Anton

After you delete all these (I believe it or not), do this:
Check the system for viruses
Clean it up with this (this is a .bat file, which means copy what will be below, paste the copied into notepad, click save as, you can save with such parameters del. bat

del /f /s /q C:\*.tmp
explorer %userprofile%\local settings\temp\
explorer %windir%\temp\
start cleanmgr.exe
pause

We wait patiently without touching anything until the windows, or rather folders, open, select everything that is in these open windows and delete them in turn in each window there will be two of them.
Let's move on:
after rebooting the computer, we clean it up with a .bat file (copy it and save it with a notepad in the OcstkaDiska.bat format ), run it !!!on behalf of the administrator!!!
in the pop-up window, put on ALL the checkboxes and click OK , patiently wait for the system to be cleaned and reboot again.
After that I recommend to make "defragmentation" Only not on the SSD drive; only on HDDs .