You can see the problem here…
The new IE promotion web site talks a lot about IE10, but if you’re running Windows 8, you’d already have it, and if you’re not running Windows 8, you can’t use it.
(Well, not yet. Apparently IE10 will be available for Win7 at some stage… there is a “Release Preview” available. I’m guessing that’s Micro-speak for “beta”.)