Steve Ballmer, while in an interview the WSJ, decided it would be good to attack Google.

I mean, come on. [Google] have one product. It’s been the same for five years–and they have Gmail now, but they have one product that makes all their money, and it hasn’t changed in five years.

So let’s look at the Windows timeline. 

That would appear to be just over 5 years between major version. 

But of course, Microsoft have a very large amount of products. For example, the Zune and the Xbox. Similarly Google, offer many more services than Ballmer are giving them credit for.

Whether it be Google Docs, Google Analytics, Google Apps, Google Video and YouTube, Google Sites, Blogspot, Google Earth.

One of the main criticisms people have about Microsoft now, is that they’ve lost their target. They’re just wandering into markets and not really doing a good job in any of them. 
This is the opposite of Google who have a main product, Search, and they’ve found many uses for this.

As you may have noticed, Google seems to be having more success with their approach.