Computer users that pass on Microsoft's new Windows Vista operating system in favor of the company's next OS release could find themselves in the lurch given Microsoft's "poor" track record for shipping new products on time, research firm Gartner is warnings its clients.

In a note, Gartner said it's been told by Microsoft that the software maker is "scoping Windows 7 development to a three-year time frame," confirming earlier new reports about Microsoft's plan for a Windows Vista successor.

But Gartner warns that businesses that decide to stick with Windows XP -- Vista's predecessor -- until Windows 7 is available may be pushing their luck. "If the release date slips, enterprises will find it difficult to fully eliminate Windows XP before ISV and Microsoft support [for Windows XP] ends," Gartner analysts write in the note.

A number of businesses and government agencies have indicated they may forego installing Windows Vista on their enterprise systems due to concerns about price, performance, and application compatibility. Some 30% of the 612 IT pros that responded to a recent InformationWeek survey said they have no plans to upgrade their company's computer systems to Windows Vista.

But Gartner, in the note published last week, says sticking with Windows XP until Windows 7 arrives is a risky strategy for IT deparments. "They should continue with plans for Vista," the research firm advises, noting that "Microsoft's track record for delivery-to-schedule is poor."

Indeed, Windows Vista was originally scheduled to launch in 2006, but did not hit the market until January of this year.

Gartner also notes that Microsoft has provided little information to date about Windows 7, other than the fact that there will be 32-bit and 64-bit versions. That, according to Gartner, means one of two things: "Microsoft doesn't really know what Windows 7 will comprise or does not want to commit publicly to what it will comprise."