What does power on password mean and why do I have one?

I have a lap top that is connected through wireless connection which is in another room. Ever since a new hard drive was put in my lap top it has asked me for a power on password. I put it in and it starts. It is not my password to start windows. I had another issue which may not be related so I will ask another... show more I have a lap top that is connected through wireless connection which is in another room. Ever since a new hard drive was put in my lap top it has asked me for a power on password. I put it in and it starts. It is not my password to start windows. I had another issue which may not be related so I will ask another ques. for that but I'm just curious as to what this poweron password is and why I have it?
Update: When I add the password it shows up a start up screen like it was shut down with a power outage and not the right way. But I do shut it off the right way, It asks do you want to start windows normaly or use last configuration that worked. Thats all I get. Sorry I am not to familiar with comp. so when you say bios... show more When I add the password it shows up a start up screen like it was shut down with a power outage and not the right way. But I do shut it off the right way, It asks do you want to start windows normaly or use last configuration that worked. Thats all I get. Sorry I am not to familiar with comp. so when you say bios it's greek to me. thanks for trying
4 answers 4