Sometimes you might have noticed that the icons are still displayed under notification area even you removed or deleted the program from your computer.
To clear the Past Items list manually, follow the steps below:
1. Click Start, type regedit.exe and press Enter
2. Navigate to the following branch:
HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\TrayNotify
Delete the values IconStreams and PastIconsStream
3. Restart the computer