Resetting password toshiba laptop qosmio g15-av501

You will need to go into the system, using the original passcode to reset it.
You have another question stating your brother set the first code, he will need to remember this code to reset it.

There are other ways to reset the password also. First you need to see what Operating System it is. If it is Windows XP there are links that explain how to bypass the password on such a computer. This explains how to change it while inside of the profile (0ne Way) and This explains how to bypass password from outside the account. There are others, but one of those should work.