Microsoft has made Solitaire free-to-play on Windows 10

Microsoft is tapping into its vast and loyal army of Solitaire players to recoup revenue lost by offering Windows 10 as a free upgrade.

Turning procrastination into profit, the company is charging Windows 10 users $1.49 a month, or $10 a year, to unlock the classic card game's full potential.

Solitaire comes pre-installed on Windows 10 machines and is free to play, but you'll need a subscription to remove its 30-second video ads, get more 'coins' for completing daily challenges, and play additional game modes.

Microsoft's decision to offer Windows 10 as a free upgrade for the first time in history came as a surprise to many, but few could have predicted that it would have such a foolproof plan on the cards.

• Check out our Windows 10 review