Microsoft seems to be in a bit of a pickle – it has a fancy, schmancy OS in Windows 7 but a majority of its prized business customers are still clinging onto the now nine years old Windows XP operating system. On Monday at Microsoft’s Worldwide Partner Conference, Tammi Reller, the CVP of Microsoft Windows, dropped the bomb that 74% of business PCs are still running Windows XP. The reason for this slow adoption was not provided but presumably it has to do with the poor reputation that has plagued Windows Vista and possibly its successor Windows 7, which, thought its not being adopted, has fared better than its counterpart in the reputation department. Economics may also play a part as businesses have apparently been slow to upgrade hardware with the average business computer boasting of 4.4 years of faithful service. Rather than take a pessimistic view, Microsoft is putting a positive spin on this circumstance and viewing it as an opportunity to compel businesses to jump into the latest generation hardware and software. Microsoft is pretty upbeat- according to CEO Steve Ballmer, the software giant expects to sell 350 million Windows 7 licenses in 2010 alone.