It is known to all that in Vista, system will auto hide inactive tray icons.This is a useful function. But as time goes on,these icons become more and more.You will see icons of apps that you used long ago,even the app was uninstalled.Now we will clean the history.

Note: the operation will clear all your personal settings about these icons

*Right-click on the taskbar and hit Properties
*In the Notification area tab you will see a customization button. Hit it

*WIN+R to run regedit
*Navigate to HKEY_CURRENT_USER\Software\Classes\Local Settings\Software\Microsoft\Windows\CurrentVersion\TrayNotify
*Here you will see two values: IconStreams and PastIconsStream. Delete them

*Open task manager. Find explorer process and end it.Run a new task explorer.
*Done.