On mine, you sign in first. Then go to the bottom left-hand corner and click on the windows coloured flag button, click on control panel, then user accounts, change password. I am not good with computers but can do this. Good luck, I hope it works for you too.
There are actually two possible passwords which your friend could be referring to.
It's possible to set a password (in the BIOS) which completely blocks access to the computer. In the (probably unlikely) chance that your friend is referring to that type of password, he'll need these instructions:
http://answers.yahoo....20080319013652AAOI5sv
However it's probably far more likely that he's referring to the password which blocks access to the Windows operating system. If so, he needs this information:
http://windows.micros...your-Windows-password
It would depend on what kind of Operating system he uses. If it's windows, you usually go to the 'Control Panel' and then 'Users' and that has the option of putting a password on it.