Compaq Presario F700 startup password problem

Hello,

I got this,compaq presario f700 from my friend! I'm not sure where did he get it but that's not the problem now! When I turn it on, It appears to be a blank screen with ''Enter Password'' on the middle! I've no idea what's the password,so do my friend! Are there anyone who could help me to hack in or break through or reset the password or anything that could help me to on it?I really needs help right now!!It has no battery on it,btw!I on it with power supply!Thx alot if anyone could help me to solve this problem!!