Two thoughts:
1) search your drive for the file with the .lnk extension. I suspect you
will find it in a startup group, perhaps under the all users profile.
See whether excluding that file works. This may not be easy--the paths to
such files typically include hidden directories--i.e. folders whose names
are hidden under normal usage.
2) It is also possible that this file is being re-created on each startup of
Windows. This is quite possible since this is a security application and
the designers will have taken precautions against easily defeating it. If
this is the case, I don't know of a way to exclude the file--what you would
need to do, rather, is to go into Windows Defender, tools, options, scroll
down using the scroll bar, until you find the list of "real time protection
options" Consider unchecking whichever of these it is that is making this
detection--perhaps one of the first two?? (You'll need to experiment to be
sure.)
This will remove the protection Windows Defender provides against the class
of malware that might be detected via this option--but it may be a better
choice than removing Defender, removing the application, or allowing
Defender to defeat the application for your kids.
You might also ask the vendor of the program about this issue--they can
apply to Microsoft to be listed as a "known spyware-free" program, and thus
not be detected in this way.
One other thought: Have you checked the option in Tools Options to be
notified about "unknown" (i.e. not classified) software? If so, see if
unchecking this option makes this alert go away. Checking this provides an
additional safety margin for the knowledgable user, but it may also raise
many alerts for perfectly safe software which is known to the user.
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