Broken laptop screen - boot straight to external monitor in Vista

"To make sure your laptop goes to the external monitor, most laptops will have a function-fx key combo to toggle through the 3 presentation video modes (laptop only, external only, laptop and external). Most laptops I have seen use a Fn-F4 or something similar. It is the key with the monitor inside of a monitor icon.

If you would like to use auto login, read below on how to enable auto login.

I don't have a vista box in from of me, so this was taken from http://www.lockergnome.com/windows/2007/02/20/configure-vista-for-automatic-logon/ :

To do so, click Start and type netplwiz in the Search field and then press Enter. Click Continue when the User Account Control window appears. From the User Accounts window that appears, verify that your own user account is selected. Clear the Users must enter a username and password to use this computer option and click OK. Provide the password for your user account when prompted and restart your computer. Vista will automatically log on with your user account."

Some laptops will automatically switch to the external monitor if they're closed and you have a keyboard/mouse plugged in. If you can scrounge up the spare parts, that's worth a try.