Bill Veghte, senior vice president for the Windows business, said during his keynote address at the annual TechEd Conference that Windows 7 RC should be the platform for users planning a client operating system migration.

Veghte said users that are already deploying Windows Vista, which first shipped in November 2006, should continue with those efforts. "Your investment will be protected, " he said, though he did not define what that protection entails.

Microsoft said last month that it will not drop Vista when Windows 7 ships, which is now for the

Microsoft said it will continue at least until January 2011 selling Vista to computer makers, system builders, volume licensees and consumers, the company said.

There have been persistent rumors that Microsoft would abandon Vista once Windows 7 ships. Vista has not sold well in the enterprise since it shipped.