It's an installable text converter option when u install Office - allows you to open .wps files directly. If you don't have it then you will need to install from the Office installation disc.
There may be other ways to get to it, like Jim is suggesting.

Personally I like Works, it's one of the few MS products that does what it says with no bollox or mind of it's own, it doesn't reformat documents for you when it feels like it, there's no stupid paperclip that tries to change stuff as you type...