Microsoft announced today that the company has sold over 525 million licenses of Windows 7 since its introduction in October 2009. The figure was made public in Microsoft's Q2 2012 earnings report, a quarter where the Windows Division posted a six percent decline from the prior period. Microsoft previously announced in September, at its BUILD conference, that it was approaching 450 million copies of Windows 7 — it appears the company sold around 75 million extra licenses in the past few months.

Windows 7 celebrated its first birthday with 240 million in sales, and the operating system shows no sign of slowing down. Traditional PC sales might have hit a bump, but the software giant is readying Windows 8 for a beta debut in late February. With the Metro interface, and the company's three screens and a cloud strategy, we'll see if Windows 8 sells as well as its predecessor.