Reinstall Windows XP using external monitor?

Hello,

my HP laptop screen is broken so I use it with my TV.

I want to reinstall Windows XP, but the external monitor doesn't work untill the Windows login.

How can I make it my permenent screen, instead of the orginal(broken) laptop screen?

I changed my grafic card settings so that I only were using the monitor. And it works fine untill I restarted the computer. Then only the broken laptop screen works, until the Windows Login.

Any idea how to get it to switch to the monitor from the moment I push "on".

Thanks!