>>Microsoft, although I'm not certain of the procedure to get them, since the Intellipoint drivers come with MS rats and are not downloadable from any of the free web pages AFAIK. The latest driver set in the retail MS packages for their wheel mice seems to work fine. I suspect that if you've registered your MS mice with MS, or got them with a system from someone like Dell, you can go to the vendor or MS and get an update.
>
>Do Microsoft Natural keyboards also have to be registered?

I don't know; if they include drivers that you'd otherwise have to pay for, I'd assume that they differentiate between owners and non-owners in some way.