I experienced this peculiar problem today when trying to activate the Power notification icon after it mysteriously disappeared from my system tray. To my amazement, the Power checkbox had become frozen and therefore I could not select and get my icon back.
When I opened the Customize Notification Icons dialog box, I found plenty of other icons lying there for applications I had removed long back – but no signs of my dearie dear Power..!
The reason behind this is the Explorer caches a list of every icon that appears through its interface and over a period of time this list could go up to hundreds or more.
The other issue is that Explorer keeps these items in memory somewhere, so it also causes bloat, but we can reset this list through the registry and by restarting Explorer. Note that this will remove any settings you had set for the icons.
To get to the dialog we are talking about, right-click on the notification icon tray and select Customize Notification Icons or go to the same through the Taskbar properties –
Run regedit.exe through the Start Menu -> Run command, and then browse down to this registry key:
Now you will see two entries in the list: IconStreams and PastIconsStream. Select both of them and delete. (You may want to take a backup with the export function before doing this) –
That’s it, done..!
All we need to do now is to restart Explorer.exe through Task Manager (Ctrl+Shift+Esc).
In order to do so, we select explorer.exe from the list and choose End Process and subsequently click on the File menu (Alt+F) and click on New Task to specify explorer.exe in the same and then press OK.
Now your Customize Notification Icons dialog box should show you a very clean list of items, but note that any settings you had will be reset to default.
Please note that some icons might disappear entirely until you reboot your computer.