How do I get my laptop to use an external monitor without logging on first?

I have a toshiba satellite pro laptop, and the screen is cracked, so I have been using an external monitor.I recently used a product recvery disk to reinstall windows. When i used thedisk it all worked and then when i restarted the laptop the external monitor only worked until the windows xp screen came on. Because I used the disk there is another screen I have to go through before windows will work again. That screen comes up on my broken laptop screen though, and I can’t see enough of he laptop screen to be able to work through the instructions on that page. DOES ANYONE KNOW HOW I CAN GET THE EXTERNAL MONITOR TO STAY ON ALL THE TIME WITHOUT HAVING TO LOG ON, (WHICH I CANT) ????thanks