Will the release of the third and final service pack for Windows XP manage to impact the delivery of Windows Vista Service Pack 1 and disrupt the momentum of Vista adoption? The answer might seem simple at first, but the fact of the matter is that there are a multitude of intersecting factors impacting the uptake of Vista, as well as XP's strong grip on the operating system market. But in the end, one thing has to be clear for Microsoft, XP SP3 will mean less Vista on the market, SP1 or no SP1. For the Redmond company, it is still a win-win situation, as it does not want XP users swapping Windows for Linux or Mac OS X, but as far as Vista is concerned the operating system will feel the reverberations of SP3.

Since its release in November 2006, and in January 2007, Vista has had a slow, but steady, general adoption rate, fueled mainly by options made by home users and sales through the original equipment manufacturer channel. Microsoft's latest Windows client did indeed underperform in terms of uptake in the corporate environment, although the company has never confirmed such a scenario. Currently, Vista is but a tad short of hitting the 10% market share milestone, a percentage roughly synonymous with 100 million sold copies worldwide.

Microsoft is also hard at work building Vista SP1 and XP SP3. The first Release Candidate of Vista SP1 has already been available for public download. The same is valid for a pre-Release Candidate version of Windows XP SP3. Despite having different official deadlines, both service packs are heading for a concomitant release in early 2008. This, of course, has not been conformed by Microsoft.

Especially with XP SP3 on the market, there will be increased resistance to migrating/upgrading to Vista SP1. Users will be tempted to ride XP for all it's got on wait for Windows 7, in 2010, now but two years away. Microsoft simply set the bar to high for Vista, and over-promised with the operating system's marketing campaign, while reality was not nearly as... Wow.

Back in mid July 2007, the Redmond company recalculated the initial 85/15 split in sales between Vista and XP to a 78/22, producing a new forecast for the 2008 fiscal year. According to this data, Microsoft's safest estimation is that XP will continue to sell, and sell well, for that matter. XP SP3 will only accentuate this trend. Of course that, as of mid 2008, Microsoft plans to no longer offer XP via the retail and OEM channels. And as Windows client sales via OEM account for over 80%, Microsoft is looking at in excess of 200 million copies of Vista next year, just from operating systems shipping preinstalled on new machines. However, the Redmond company is actually looking to dislodge market share from under XP. So, how about it? Which way will you swing, XP SP3 or Vista SP1?