The June 26 start date for Best Buy's promotion is also the date when the . That separate marketing campaign will provide free or discounted upgrades to Windows 7 for people who purchase a Vista-powered PC between June 26 and Jan. 31, 2010, according to TechARP, a Web site that has repeatedly accurately called Microsoft future plans.

Microsoft declined to confirm the Best Buy memo's details last week, saying, "We're excited to share additional details regarding these programs soon, but do not have additional details to announce at this time."