I let my brother use my laptop,and he has put a bios password on it and now he can't remember it ,my laptop is a toshiba satellite pro l20,can someone tell me how I can get it working again and that's not going to cost?

I don't know what to tell you. If it has w warranty on it send it back to the Toshiba Computer Company, for a bios password removal!

I might have another solution. At least it worked on my desktop.
I took the battery (inside the computer, the small nickel sized silver disk some where inside the case) out for about thirty minutes and that reset default settings.
Good luck.

You need to contact Toshiba. The battery trick won't work on a laptop. See this thread:

https://www.askmehelpdesk.com/other-security/toshiba-laptop-bios-password-cracker-12222.html?highlight=toshiba+bios