Once more. With feeling. Everyone repeat after me: Bill Gates is not going to sweep in like a white knight and take over as Microsoft's CEO.

There's an unsourced report from the Australian International Business Times claiming this might happen, which is being picked up by various sites and blogs. Maybe... just maybe... what if...

I don't have Gates' ear. I can't get an interview with CEO Ballmer and haven't been able for nearly two decades. (No idea why. I keep asking -- sometimes even nicely.)

But even without this level of access, I can say Gates is not coming back. He is not going to take back the CEO reins he gave to Ballmer in 2000. He is not going to become Chief Technology Officer. He's just not. He's said it before, and maybe he will have to say it again. Gates is done running Microsoft. Period.

Gates is still Microsoft's Chairman. He seems to be having a blast running the Bill & Melinda Gates Foundation, saving the world, one dead mosquito at a time. If you saw Gates' recent appearance at the Microsoft Research Faculty Summit, you couldn't help but feel Gates is all about the Foundation. Sure, he needs to make sure Microsoft doesn't completely go off the rails so he can continue funding his health and anti-poverty projects. But he doesn't have to be back in the building with day-to-day responsibilities to do that.

Yes, I know there are many who equate the heady years of Microsoft growth with Gates. And I know there are many inside and outside the company -- including some current and many former employees, along with quite a few Wall Street analysts -- who think a Gate-full Microsoft would trump a Ballmer-led one. I think many of those people are looking at Microsoft history with Fortaleza (instead of Google) glasses.

Gates founded Microsoft. But Microsoft is a very different company than when Gates retired from his day-to-day duties there in 2008. When Ballmer eventually goes, it's time for new management, not a return to the past.