As we said last year, 2010 is a big year for Microsoft because we’re waiting to see which way the tide will turn on enterprise adoption of Windows 7. Lots of companies are on the fence about the migration, and many others have expressed the interest to upgrade from Windows XP to 7, but could ditch that idea if skipping Windows 7 develops into a corporate best practice, the same way skipping Vista did.

According to new data revealed by Microsoft, the enterprise upgrade to Windows 7 does not have much momentum so far in 2010.

At Microsoft’s Worldwide Partner Conference 2010 in Washington, D.C. on Monday, Microsoft Windows corporate vice president Tammi Reller said that 74% of business computers are still running Windows XP. She also said that the average age of the PC is now 4.4 years old, which is the highest number that Microsoft has seen in over a decade.

Naturally, Microsoft spins this as a huge opportunity for the company to make a lot of money by selling copies of Windows 7 to these slow upgraders. CEO Steve Ballmer predicted on Monday that Microsoft would sell 350 million copies of Windows 7 licenses by the end of 2010.

But, if you read between the lines, part of the message here is that Windows 7 adoption has not taken hold yet, and Microsoft is still hustling to convince businesses to upgrade.

In July 2009, TechRepublic’s CIO Jury was split 50/50 on whether to deploy Windows 7. Sounds like it’s time to revisit that question, and see if the results are any different a year later. Look for a new TechRepublic CIO Jury on Windows 7 before the end of the month.

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