How do I secure my laptop?

[Lucky Luc]

My mom just received a laptop for her and my dad to use. It has two user accounts for them set up with a password code. My parents do not want anyone else to be able to use the laptop for security reasons.

Now my question is:
Is there a way to set up a password so that the laptop won't turn on to the user name screen? Apparently one of my brothers was using the laptop while they were gone. And you can't get in without their passwords. So we don't know how he got in.

Any ideas on what they can do to keep their laptop safe?

Thanks guys.

LL