it seems that the explorer.exe process is not always starting with windows. If it happens again try, pressing Ctl + Alt + Del. And select FILE then "New Task", the type in "Explorer.exe". then select OK. ur Icons and taskbar should return. U can't really control explorer.exe boot but u can enforce it. Got to C:\Windows\ and right click "Explorer.exe", select "Send to" then "Desktop". then just go to your desktop and drag that new icon over the start button, then over "All programs" then drop it on to the start up" folder. This should enforce explorers start.