Windows 95 launched 20 years ago today to the beat of "Start Me Up" by the Rolling Stones. It became the theme tune of a massive launch that saw thousands of people lining up at midnight to purchase a copy of Windows 95 on a CD-ROM. Microsoft spent millions on Windows 95 advertising, and "Start Me Up" featured in most TV commercials at the time. Flash forward 20 years, and Microsoft is giving the song away today to commemorate the launch of Windows 95. If it was good enough to make former CEOs Steve Ballmer and Bill Gates dance (terribly) on stage 20 years ago, it's good enough for your music collection. You can download it until 11:59PM PT tonight from the Windows Store.