By the end of the next quarter, Klein reported in July, the 40% had grown to 50%.

Rather than adopt Windows 8, companies with enterprise agreements will simply downgrade newly-purchased PCs to Windows 7, Silver and Cherry agreed.

"Those who have finished a Windows 7 rollout will probably want to stay homogenous," said Cherry.

Their expectations about Windows 8 and downgrades are due in no small part to factors outside the operating system's control.

Because of Vista's failure to take hold, Windows XP had an unexpected long life. Then when Windows 7 launched, the pent-up demand for new machines, the looming 2014 end of support for XP, and positive reviews for Windows 7 kick-started migrations of the latter in 2010.