i purchased this hp with windows 7 and when i first turn on laptop a black screen with a white bar in center asks for password. its the old owners password id like to remove it permanently its very annoying
That sounds like the BIOS password. Removal is done in the BIOS but 2 things.
1. No full model number so I can't see if it's documented.
2. Sometimes there is no document so you explore all the BIOS pages.
If it is the BIOS password, there is a means to reset the BIOS flash memory, erasing the old password, but it will require removing the cover and keyboard, and then shorting out a couple of contacts on the motherboard. My grandson knows how to do this, but I haven't had to deal with that. My attorney gave him one of his HP laptops - it took him about 5 minutes to do this... If it is the operating system password, then you may need to reinstall the OS and set your own admin/user password.