Brian has an old computer with Windows 2000 and he recently got a message from Firefox that it no longer supports his operating system. Leo says that the computer is pretty old, and Microsoft has decided to end support for that OS. Unfortunately there's not much he can do.
Since Windows 2000 is so old, it's probably not going to hurt anything to just use it as it is. Leo says nobody is really writing exploits to it anymore. Leo also says he could put something on it like Puppy Linux and breathe new life into it. Leo and Iyaz showed how to install Puppy Linux on an older computer in an episode of Know How.