Windows Vista is scheduled for consumer availability in six days. However, the latest operating system from Microsoft will have to displace Windows XP from its dominant position on the market. This because Windows Vista's main rival is not Mac OS, or Mac Intel or Linux. Microsoft's own Windows XP is the sole factor that stands before Windows Vista and the lion's share of the operating system market.

In this context, analyst Gartner has forecasted that Vista will not become the dominant presence on the OS market until 2009. In fact, in the first month of availability, Microsoft's Software Assurance customers failed to acquire Windows Vista via volume licensing, at a rate that would overshadow Windows XP's market performances.

Additionally, Gartner predicted that Windows Vista will only find its way onto 12.3% of the worldwide desktops. Windows XP, currently accounting for a share of 85.3% of the OS market, is also expected to diminish its dominance.

With Windows 2000 and Windows 98, alongside Windows NT and ME, users have a great opportunity to upgrade their operating system together with the adjacent hardware. However, Windows Vista will erode mainly Windows XP's market share.

Windows Vista's mediocre performance in the first year on the market is expected to pick up following the release of the first Service Pack for the operating system in the second half of 2007. Microsoft has pushed back the release of Windows XP Service Pack 3 for 2008, but the Redmond juggernaut will make a trade-off and will kill XP in order to breathe life into Vista. Gartner's forecast sees Vista at 55.4% of the operating system market in 2009, and XP at 40%.