is it a power on password ? soon as you turn the computer on it ask you ?
if it is, then you can try going into the bios, sometimes says when you power it on, press del or f10 etc to enter setup, you can see if you can disable it there, but unlikely you will, probably will need a cmos battery taking out or a jumper on the motherboard, or you might not be able to do it at all, may need some sort of dongle
what make and model is it ?
or does it start to load windows, and ask you for a user name/password ?
if it does you can go into safe mode, and download a program off the net that will reset the windows admin password
