I brought a HP laptop dv500 a couple of year back which had the Bios password set, this powershell script changed it to a password I could use
$passChange= Get-WmiObject -computername "Insert Computer name" -Namespace root/hp/instrumentedBIOS -Class HP_BIOSSettingInterface
$passChange.SetBIOSSetting('Setup Password', '<utf-16/> InsertyourownPassword')
