According to Forrester Research in Cambridge, Mass., the OS that Vista is replacing, Windows XP (introduced in 2001), took more than four years to be installed on a majority of PCs. Today it still occupies only 76 percent of the PC market. Older versions of Windows, such as Windows 2000, make up most of the rest.
Forrester predicts Vista will be adopted at a similar or slightly faster rate than was XP. Twelve million American households will have Vista by the end of 2007, Forrester says, and 73 million by the end of 2011.
Vista's impact is bound to reverberate throughout the world of PCs as new hardware and software takes advantage of its capabilities, analysts say. Every dollar that businesses and consumers spend on Vista is expected to create $18 in revenue for related products and services, predicts a Microsoft-sponsored report from tech research firm IDC.
In the years ahead, nearly all PCs will migrate to Vista as Microsoft drops its support for earlier Windows operating systems, says Ben Gray, a Forrester analyst.
Early sales are expected to come mostly from consumers. Businesses are notoriously slow to adopt a new OS. A Forrester survey of more than 450 North American enterprises earlier this year found 11 percent said they would switch to Vista within six months of its release and 29 percent within a year. But 60 percent said they either would wait longer than that or had no plans to switch at all.
Because businesses must test how their own applications work on Vista, it could take them six to 18 months to get ready to deploy, Mr. Gray says.
PC owners will be able to buy a copy of Vista to install on their current computer. But the computer will have to be "Vista ready" – most likely a fairly new machine with plenty of memory and other robust technical specifications. To add to the confusion, four versions will be available – Home Basic, Home Premium, Business, and Ultimate – each with its own set of features and requirements. Microsoft's Vista website offers advice (microsoft.com/windowsvista /getready) that can help determine which version, if any, an existing computer will be able to run.