Steve Ballmer seems confident that businesses will adopt Windows 7. Of course, three years ago, Microsoft's CEO was sure that companies would deploy Vista, and look how that played out. Will he be right this time?I pushed Ballmer on that question in a recent interview. According to an InformationWeek survey of 1,414 IT pros, only 16% plan to deploy Windows 7 over the next 12 months. "You have your work cut out," I said.

Ballmer argues that businesses will be compelled to roll out Windows 7 for a variety of reasons: It's less expensive to operate; end users will demand its new features and capabilities; and there's a compelling business case around increased productivity and business innovation.

Says Ballmer: "I don't think this will be a question in the case of Windows 7 of, 'Should we?' It will be, 'When should we?' There will be a strong view very quickly that says, 'We should.' "

For businesses contemplating the move, there are issues to deal with: the cost of deploying Windows 7, applications compatibility, PC hardware requirements, employee training, IT department readiness. But Microsoft customers have been through this before; as Ballmer says, "It's software business as usual."

Businesses that aren't ready for a companywide Windows 7 upgrade can bring in the OS gradually by including it on new PCs as part of the normal refresh cycle.

The strongest case for Windows 7 may be the fact that the widely used Windows XP is now eight years old. Businesses simply can't continue to operate effectively running old apps on an outdated operating system, and Ballmer knows it.

Ballmer says he's "not scared" by InformationWeek's survey results showing that many IT pros don't have plans to deploy Windows 7. For more, see the full interview here.

[Find out when Windows 7 will be right for your enterprise. If you're weighing whether or not to migrate to Microsoft's new operating system, check out InformationWeek's Business Case For Windows 7.]