Question : Problem: BIOS problem

I'm trying to fix this problem for a friend and need some help, her little brother got into the bios and put a password on the hard drive and now he can't remember what it is.

this bios has passwords for system, admin, and for each of the hard drives.
I have found the jumper to disable passwords but it does not remove or reset this hard drive password, only the others.

I also tried unplugging the pc and removing the battery, that didn't work.

Answer : Problem: BIOS problem

You need to contact Dell first and they will tell you If ownership is in question. Then you would have to perform a transfer of ownership form found here before they will take it to the next level.
http://support.dell.com/support/topics/global.aspx/support/change_order/tag_transfer?c=us&cs=rc956925&l=en&s=gen

If you cannot provide proof of ownership then you are looking at  replacement of the hard drive.
If there is data that needs to be accessed on the hard drive, then this would require a professional service.
http://www.nortek.on.ca/Password%20Removal/PasswordRemoval.aspx