Businesses are continuing to avoid Vista, the latest research from Forrester Research reveals.

The researcher says that continued loyalty to Windows XP remains a bigger hindrance to Windows Vista sales than Mac OS X and Linux.

"The big story isn't that 32 percent of the companies we surveyed said that they would start Vista deployments by the end of next year," said Forrester analyst Benjamin Gray. "It's that companies have been hugely successful in standardising on Windows XP."

According to a survey of nearly 600 European and US companies that have more than 1,000 employees, 84 percent of all their PCs now run Windows XP, up from 67 percent the year before. While XP may have peaked, Gray warned not to bet against the six-year-old operating system.

"There are plenty of companies looking forward to XP SP3," he said. That next hot-fix and patch rollup is to ship sometime in the first quarter of 2008, Microsoft has said, and it will reportedly be XP's last service pack.

"Vista's biggest competition isn't Apple or Novell or Red Hat; it's Microsoft itself, it's XP," Gray said. So enamoured of XP are businesses that Microsoft may feel obliged to extend the operating system's mainstream support past its current April 2009 expiration date. "I wouldn't be surprised," Gray said, although it might require some additional pressure on the company by its largest customers.

Still, XP will eventually get the boot in favour of Vista, Gray said. "Vista isn't a matter of if, but of when and how," he noted.

Nearly a third of the polled businesses said they would begin deploying Vista by the end of 2008, while another 17 percent said they would start in 2009 or 2010. But more than half of all companies remain nervous about Vista, according to Forrester's data. A year after Microsoft released Vista to duplicators, 38 percent of companies claimed they had no plans at this stage to deploy the operating system. Another 14 percent said they just didn't know.

Gray also echoed other analysts who last week said Vista plans had been significantly scaled back by most companies. "That's absolutely the case. In May 2006, 40 percent of the companies we surveyed said they planned on deploying Vista within the first year of its public life," Gray said. "Forty percent were planning on deploying, but by the end of 2007, only 7 percent will have started. Enterprises are absolutely pulling back from their very, very aggressive deployment plans."

He attributed the lowered expectations to a lack of detailed information about Vista in 2006; too-high prices for PCs with 2GB of memory, which is essentially the minimum needed for Vista, according to company managers; and a larger-than-expected number of incompatible applications.

"Application incompatibility is a big, big headache," Gray said, citing reports from companies preparing for a migration to Vista. Those firms said applications incompatible with Vista made up between 10 percent and 40 percent of their software portfolios. "That's causing a lot of XP shops to take a wait-and-see approach to Vista."

But Gray said he was convinced Microsoft will triumph in the end, if only because it has virtually no competitor worth the name in the enterprise market. "Linux and Mac have 1 percent or 2 percent, and in some cases, such as Europe and the largest corporations, they don't even register," he said. "Microsoft owns this space, and I don't see that changing."