Microsoft officials announced on January 18 that this will not be the case.
Currently, Microsoft is charging $40 for an upgrade license to Windows 8 Pro from Windows XP, Windows Vista, or Windows 7.
Testers who've been working with Windows 8 preview builds also have been eligible for the $40 upgrade price. The Windows 8 preview builds (Developer Preview, Consumer Preview, and Release Preview) all expired earlier this week. After that time, users with those builds will notice that Windows 8 will restart every hour "until they've installed a released (RTM) version of Windows," a Microsoft representative confirmed earlier this week.
Here's information on what users upgrading from XP, Vista, and Windows 7 can expect to migrate (and not) when upgrading to Windows 8.
This story originally appeared on ZDNet under the headline "Microsoft's Windows 8 upgrade promotion really is ending on January 31."