Excel and Word are Microsoft's expensive office applications so you won't get a free legitimate copy anywhere.

If you are a student or have a kid you can buy the student edition of Microsoft office for £70 at PC world at the moment. In fact, I think they may now call it the home edition so, as long as you only use it for personal stuff, you don't even need the kid any more.

As an alternative Sun do an Open Office suite that is said to be fully compatible but I've never tried it.