The boot screen is the screen that displays during the bootup (startup) of Vista before the logon screen this is hidden by default in vista also called as Aurora Boot Screen.
Enable Aurora hidden Bootscreen in Vista follow these steps
Click on the start>run type msconfig press Enter.
Once the System Configuration tool loads on – click on the Boot tab.
Under Boot Options check “No GUI boot”.Click apply and then OK and restart your computer to see the new boot screen.
You can Set the Time Out to 15 sec or lower it even boots much faster.
Vista Hidden boot screen looks similar to the following screen