Do the math: 175 million copies of Windows 7 isn't that impressive

By simply counting the number of new PCs sold, it's obvious that businesses aren't flocking to Windows 7 in droves

Where's the beef? That's what I want to know.

Last week Microsoft reported amazing results for the quarter ending June 30, 2010. The numbers almost defy visualization: $16 billion in revenue for the quarter, up 22 percent from the same quarter last year; $62.5 billion revenue for the year. Key to the quarter's soaring sales: Microsoft sold 175 million copies of Windows 7 since its release on October 22 of last year.

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Microsoft doesn't break out sales figures -- how many licenses crossed store shelves in boxes; how many came gratis with corporate Software Assurance plans; how many went along for the ride with new PCs. But at seven licenses per second, it's hard to question Windows 7's supremacy.

Or is it?

I was playing with some numbers (Excel is a dangerous weapon for inquiring minds) and something odd struck me. The figures don't add up.

In the push-me-pull-you world of new PC sales, Windows 7 is widely credited with spurring record sales of new PCs. Most of those new PCs come with copies of Windows 7 -- which is why the discrepancy really struck me.

Last week, IDC reported that 2Q 2010 PC sales hit 81.5 million units, up 22 percent from 2Q 2009. Rival Gartner pegs 2Q 2010 PC sales at 82.9 million units, up 20.7 percent from the same quarter in 2009. No matter which number you choose, it's obvious that Windows 7 has driven lots of new PC sales. (Not all of those new PCs ship with Windows 7, of course -- both IDC and Gartner include Apple products in their counts and a handful of netbooks still ship with various flavors of desktop Linux.)