Can't remove machines from Computer list in Network View

[MKop]

The group or grid view in the Network section lists quite a few machines that were retired/removed.   Some clean up on my part was needed as I had some stale computer names in AD and in DNS.     I went through and did some house cleaning and removed the old entries.   

In Avast, these entries are still listed.   So I went through the list and used 'Remove Computer(s)' on each entry I wanted to remove.   I clicked into another section (i.e. into reports) then back into Network and all the entries had returned.  I cleared cache and restarted the browser with same results.   

I ran the Clean Database job from avast with no change. 

#1) How is this list created?  AD listing?  DNS?  Its not an IP scan....
#2) Any ideas as to why these entries keep returning?

[lukas.hasik]

The group or grid view in the Network section lists quite a few machines that were retired/removed.   Some clean up on my part was needed as I had some stale computer names in AD and in DNS.     I went through and did some house cleaning and removed the old entries.   

In Avast, these entries are still listed.   So I went through the list and used 'Remove Computer(s)' on each entry I wanted to remove.   I clicked into another section (i.e. into reports) then back into Network and all the entries had returned.  I cleared cache and restarted the browser with same results.   

I ran the Clean Database job from avast with no change. 

#1) How is this list created?  AD listing?  DNS?  Its not an IP scan....
#2) Any ideas as to why these entries keep returning?

ad 1; it's AD listing
ad 2, do not Delete them, move them to Unmanaged group

[isgtz]

I have a similar problem reported above:
Am during the holidays on a WIFI router and suddenly have another PC on my network.
I know that this person who share the house but still I don't want to have other computer appear in my network everytime I connect to a WIFI somewhezre (BTW, it never happened before).

How can I remove his PC from network?

Thanks