The much-maligned Vista OS runs on almost one out of eight corporate desktops 28 months after its release, according to a Forrester Research report released today.
Apple's Mac OS X also made gains, partly at the still-dominant XP's expense, but that will start to change in the fall after the release of both Windows 7 and OS X 10.6 "Snow Leopard," according to the analyst firm.
Vista's share grew to 11.9 percent at the end of March, up from 7.3 percent nine months earlier. Vista was made available to large organisations and businesses on November 30, 2006, and to consumers and small businesses two months later.
Growth, while slow to pick up among businesses as with all new Windows releases, is now "steady," wrote analyst Benjamin Gray.
Forrester's figures today appear to support an earlier report showing that despite Vista's bad reputation, North American and European IT managers were "slowly warming" to Vista.
Now, "desktop operations professionals who have already standardized - or are in the process of standardizing - on Windows Vista are comforted by the fact that these investments will ultimately pay off with greater compatibility with Windows 7," Gray wrote.
Overall, Windows' share of corporate desktops remained a dominating 96.2 percent, slightly down from its 96.8 percent share in July 2008.
XP's share was 86 percent. It is "the OS that just won't quit," wrote Gray, despite "signs of extremely advanced age."
"Although Windows XP use continues to slowly fade, we expect the majority of Forrester clients to stick with it until they're ready to make the jump to Windows 7, despite Windows XP SP2 having already entered its extended support phase and Windows XP SP3 following suit on July 7, 2010," Gray wrote.
Apple Inc.'s Mac OS X ran on 3.6 percent of corporate desktops, up from 2.7 percent nine months earlier.
"As impressive as this growth is, just imagine the possibilities if Apple actually formulated an enterprise strategy - something it seemingly has no intention of doing," Gray wrote. He also said these statistics are probably an undercount because of the many Macs primarily running Windows XP under virtualisation during work hours that are then counted as Windows machines, not Macs.
Gray wrote that many businesses are "in a holding pattern," waiting for the arrival of Windows 7, which Microsoft was expected to be released to manufacturing today, as well as the release of OS X 10.6 "Snow Leopard" in September.
Gray expects large enterprises to start deploying Windows 7 in late 2010 to early 2011, or 12 to 18 months after its release. Many of those deployments will be "big bang or forklift" ones, rather than rolling refreshes, Gray said, due to the many companies that have been holding off on upgrading their desktop PCs due to the economic downturn.
Forrester's numbers come via its quarterly survey of 85,000 desktop PCs at 2,600 companies.
Windows 2000 was on 1.2 percent of business desktops at the end of March, with other versions of Windows holding 1 percent.
Linux continued to decline, falling to just 0.1 percent of the corporate market. Gray said there was some hope for Linux in the form of thin clients and netbooks.