Thanks for your quick reply but it doesn't work. I think this problem occurred after I ran iolo System mechanic Advanced system settings (tried to add Open windows command here...)
Normally when i move my mouse over an item like Getting started or Sticky Notes, it will list out a list of items. But it's not working now :-s I don't remember what I've changed. Go to Taskbar and Start menu properties and I have both privacy checkboxs checked Pls help me! Thank you very much