in the Windows 7 Help center? It usually displays as an icon in the Notification Area, (where the clock is). I'm not sure if I have used the right name, it's the icon that looks like a flag.
I'm just guessing that if any issues remain, eg outstanding updates, other problems, Win 7 may be calling the Taskbar back up to notify you.
Other than that, I can't say.
I constantly have a problem getting the taskbar to autohide. I go to the taskbar properties and check the autohide box and the lock the taskbar box, and then click apply. The taskbar consistantly refuses to autohide until I reboot the computer and then it will only autohide once and then quit autohiding. Anyone have any suggestions?