And sooner or later that "adguard" application will get in the way of something else legitimate and then you will want to uninstall the blocking software.
Or adguard becomes corrupted in some manner likewise causing problems.
And even with adult sites blocked there will always be new ones that the block will not block.
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"I know of no method an admin account can do, that an admin account cannot undo. " per
@USAFRet .
Seconding that.....
Basically the requirement to do what you what to do becomes giving up admin rights to your PC.
If the concern is that great about you uninstalling the software then setup a
user account for yourself on your PC. An account that does not let you install or uninstall software.
Then have a trusted friend or family member change the PC's admin account password, write it down, and safely store the password where you cannot easily get the password without their assistance.
Cumbersome indeed and overall problematic..... but doable to some extent I think.