Clean the Taskbar Notification Area Icon Cache in Windows 7
Launch the registry editor
Navigate to the HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\TrayNotify key
Delete the IconsStream and PastIconsStream values in the right pane.
Finally, you’ll have to log out and log back in (or restart Explorer.exe) for your changes to take effect.
Reboot System for changes to take effect if logout/login does not work
