I decided to change my dual boot setting from auto countdown to wait until user select, hence I uncheck the boot setting. Oops Mistake Now I can't perform dual boot, this is because it always boot the default OS. In my case it's Windows XP, now I have a problem... I can't change the boot setting in XP because Vista use a new book manager The Boot.ini in no more there... Luckily found this tools which allow me edit Vista Boot settings in XP.
Introducing VistaBootPRO 3.1 from PROnetworks. Download from here.