You think the ShamWow guy is persuasive? Wait till you see this YouTube video of Microsoft CEO Steve Ballmer telling viewers why they just have to buy Windows.

Mr. Ballmer announced his plans to retire within the year, on Friday. Microsoft lost some of its edge in making the shift from a desktop-centric world to things Internet and things mobile, and the company could well benefit from fresh eyes at the helm. Still, end of an era.

The video was uploaded by user Gabriel Rezende on YouTube.