Is there a way to START (run) a program just after a reboot or before the log-gin(password) screen?
I have a Home Surveillance System that has to be running in order to get into the system remotely.
So if the system reboots or someone shuts down my computer at home, I cannot getting into the system remotely. The program runs only under my user name and password, which I don't want to give to anyone.

P.s-Running windows xp.If someone shuts it down you have no options.

If it reboots and you want ijust to start up there's no need for an Administrator password, so just have it boot directly into your account, which it will do by default if there is only the Admin account and no password.

Have a read:

http://www.kellys-korner-xp.com/win_xp_passwords.htm

You can't have it both ways - a secure system with password LOGIN and a system that will go directly to functionality.VNC services provide remote connection possibilities and start as a service (i.e. are available shortly after bootup, and before logon).  Follow the link in my SIGNATURE to the Software FAQ, and look for UltraVNC.