The link to install it is sent in the same email as the unlock key, I assume you've installed it?

If so, it's set up as your active screensaver, so to see it just stop touching your computer for a while.

Or: Go to Start->Settings->Control Panel->Display Properties and click the "screen saver" tab. You should be able to select it if it wasn't selected already (it should be) and click Preview to see it.