The upgrade program will run from June 2, 2012, to Jan. 31, 2013. People who buy a new computer with any version of Windows 7 installed during that period will be able to purchase Windows 8 Pro, the higher-priced of the two global retail editions, for $14.99. The upgrade to Pro will be fulfilled after the official launch of Windows 8.

Microsoft will offer the deal to computer buyers in 131 markets, including the U.S. and Canada.

The announcement came as no surprise.

, news leaked of the deal when CNET, citing unnamed sources, said that the upgrade offer would launch in early summer, most likely around the time Microsoft delivered Windows 8 Release Preview. That sneak peak showed up on Microsoft's servers today.

Several days later, Windows blogger Paul Thurrott chimed in, saying Microsoft would .