Compaq presario v1000 starting problem

Question

can any one help me in solving my problem?. i have compaq presario v1000 with win xp OS. the problem is that it is not starting at all. i mean that when ever i press the power button the HARD DISK light is ON for 3 OR 4 SECONDS, the FAN also STARTS for 3 OR 4 SECONDS then the laptop comes to an HALT, there is no action at all and the FAN STOP and the HARD DISK LIGHT is OFF.
the last time i used the laptop and i SHUT DOWN it properly and there was NO PROBLEM at all with the laptop.
please any one help me.ill be greatfull.