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Microsoft promised a free Windows 10 upgrade to legit and licensed Windows 7 and Windows 8.1 customers. The updates will appear on these millions upon millions of machines on a staggered rollout basis. Microsoft says 'Your notification to upgrade could come as soon as a few days or in a few weeks.' Which is just not acceptable, but there's a way to trick the system into updating ASAP.
Good thing about this method is that it works even if you haven't signed up for a 'reservation' to receive the free update (just means that you'll need to download a larger file). Hit jump on a quick how-to to getting Windows 10.