some icon in window button show as program icon

[teguhteja]

Hi!
You mean the two window icons?
They show like this when you install manually an App.
For some reason, some Apps fail to register their icon.
All you can do is identify the Apps and then manually change their associated icon, if you know where to get those from.
Sometimes you can do this by right-clicking on the TaskBar then choose "Properties". If you edit the launcher and change the associated icon, you'll have pretty much any icon you want from the stock or, point to a custom icon.
Another way is to use DConfEditor, but it's more difficult.
Editing a launcher, is way easier.
Maybe the other people around here tested some other better solution.
Until that, I hope at least this will help a little.
Regards!

Hello Şerban S. Thank you for your reply and explain
I am already change the icon into .xpm extension but not work 
and try using dconfig but confuse how to use it for change icon

i am find how to use DConfEditor and found the icons in
/usr/share/icons and ~/.local/share/icons directories.
when i check the icon already there are.

Maybe i will wait someone answer this post