The main issue with the window that lists all the notification area icons is unused or even
uninstalled software can leave entries behind and it can get a bit messy. Although those redundant icons won’t appear in either the main or hidden notification areas, it’s recommended to remove them if there a number of unused entries. There is no way to remove anything through the select icons window and it has to be done manually. Here are 6 ways in which you can do it.
Note: An issue with removing unused notification area icons is they cannot be selectively removed and all have to be deleted at once. This isn’t a major problem as used applications will add their icons back into the area. One thing you do lose though is the custom setting for icons to be shown or hidden, so you will have to reconfigure the icon settings through the notification window.