The Windows Calculator is a free calculator provided on every version of Microsoft Windows since Windows 95. It was invented by the Microsoft corporation and is standard on any Windows PC in existence.
It can do what most conventional calculators do; the Windows Calculator can add, subtract, multiply, and divide. It can also square-root.
The Windows Calculator also has a Scientific setting, allowing it to use more advanced settings such as "Hex", "Dec", "Oct", "Bin", "Inv", "Hyp", "Sta", and "F-E".
More recently, in Windows 7, the calculator gained a finance mode, as well as a more friendly user interface to calculations, and many other changes,