With 2007 drawing to a close, it appears that Microsoft will be logging about 100 million Windows Vista licenses sold in the OS's first year on the market. (The company reported 88 million licenses sold in October.) That's not too shabby, I guess, but with PC makers expected to sell more than 250 million PCs in calendar year 2007, it's unclear how Microsoft was unable to capture at least double that number.

The latest theory is that Microsoft focused too much on Vista's security rather than its gee-whiz eye candy, and this after previously focusing the last major client OS update, Windows XP SP2, on security as well. I'm not sure what to make of this contention. On one level, I agree that Vista needed more demo-friendly features to attract PC owners into upgrading more quickly than they have. But on the other hand, Windows was in dire need of a security makeover. And it appears that Vista's security prowess has done the trick. Despite some complaints about the intrusive User Account Control (UAC) feature, Vista is clearly more secure than its predecessors out of the box.

But this brings up a related point. If Vista is indeed so much more secure, why has corporate adoption of the OS lagged so obviously? We repeat the mantra about enterprises always waiting for the SP1 release of an OS before upgrading as if that actually has any meaning, but will the impending release of Vista SP1 (due in Q1 2008) really make that much of a difference?

I don't believe it will. Microsoft claimed early on that the Vista value proposition wasn't going to change with SP1, and sure enough, this collection of bug fixes and minor improvements doesn't include any major new features at all. SP1 is instead a steady progression of small improvements to the core OS, the sort of incremental update we've historically expected from Microsoft service packs. I think the real issue with Vista isn't so much that it's not good but rather that XP is still good enough. Over time, XP will be forced out of businesses due to sheer attrition, but by back-porting some key Vista technologies to XP to appease its best customers, Microsoft has pushed the effective XP expiration date out more than ever before.

It's an interesting situation and one that, I believe, is unparalleled in Microsoft's history. The migration to Vista may be the longest upgrade cycle since the first version of Windows NT was launched almost 15 years ago. And it has almost nothing to do with perceived problems with the upgrade.

RC1s, All Around
In the past week, Microsoft took the unprecedented step of releasing near-complete versions of three OS upgrades, so now is the ideal time for testing each version. These releases include Windows Vista SP1 Release Candidate 1 (RC1), which will be made publicly available this week; Windows Server 2008 RC1, which is publicly available right now; and Windows XP SP3 RC1, which is now available to TechNet and MSDN subscribers. (It's unclear whether this release will be made public.) I've written up something about all three releases on the SuperSite for Windows (http://www.winsupersite.com/ ), but the mile-high view is that none of them is a dramatic change over what came before. Vista SP1, as noted above, is mostly fit and finish and compatibility and performance oriented. Windows 2008 saw all its major new features added in previous beta releases, and is now feature complete. And XP SP3 is a rollup of the several hundred hotfixes that Microsoft has shipped since 2001. That said, all three are now more complete and refined than ever before, not to be mention more widely available.