cannot turn tamper protection on and CPU usage drops from 80% to <10% when i open taskmanager

"I have noticed my CPU usage drop every time I open task manager, from 74% to 1% when i just have a browser open to write this post."

That behavior, by itself, doesn't indicate that your computer has been attacked.

Windows (and your apps) perform housekeeping when you are not actively using your computer. Once you return to actively using your computer - by launching Task Manager , for example - that activity is quickly shut down so that the computer's resources can be made available to you.

If you suspect that your computer has been attacked, scan the computer with security software, like Microsoft Defender.

Hi, thank you for replying, in this case, can you please check the System logs on the PC so I can further examine the root cause of the issue?

To share the System logs, please follow the steps in the link below:

Press the Windows key + X, then select "Event Viewer"

Click the drop-down of "Windows logs"

Right-click System > click Filter Current logs > Check: Critical, Warning, and Error > Hit OK

On the right pane, click "Save Filtered Log File As..."

Save the System logs file to your desktop and share it by following the steps from the link:

https://support.microsoft.com/en-us/office/share-onedrive-files-and-folders-9fcc2f7d-de0c-4cec-93b0-a82024800c07

Note: You can also use your preferred cloud storage to upload and share the logs.

Hi, I'm Bernard. I'm happy to help!

It’s normal for the CPU usage to briefly increase when you first open Task Manager and then quickly drop back down. When Task Manager opens, it needs to check and load information about the different apps, services, and processes currently running on your device. This can temporarily use more CPU resources, which is why you may notice a short spike.

If the CPU usage goes back down shortly after Task Manager finishes loading and stays at a normal level, this is generally not a cause for concern. Since you’ve already completed an offline scan, have you noticed any other issues, such as the system running slowly, freezing, or experiencing lag while using the device?