How to prevent children from bypassing Parental control

First, protect the settings with a password. This will prevent any changes to the AdGuard settings.
Then create a non-admin account for your child to prevent them from force closing AdGuard via Task Manager.
Alternatively, you can restrict access to Task Manager through the Registry Editor:
Press Win + R, type regedit, and press Enter to open the Registry Editor.
Navigate to: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Policies\System
If the System key doesn’t exist, right-click on Policies, choose New → Key, and name it System.
In the System folder, right-click on the right panel and choose New → DWORD (32-bit) Value.
Name the new value DisableTaskMgr.
Set its value to 1 to disable Task Manager.
Restart your computer for the changes to take effect.
To enable Task Manager again, simply change the DisableTaskMgr value to 0 or delete it.
Downloading AdGuard To install AdGuard, click the file indicated by the arrow Select "Open" and click "OK", then wait for the file to be downloaded. In the opened window, drag the AdGuard icon to the "Applications" folder. Thank you for choosing AdGuard! Select "Open" and click "OK", then wait for the file to be downloaded. In the opened window, click "Install". Thank you for choosing AdGuard!
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