The user might choose to override some of the values associated with the current culture of Windows through the regional and language options portion of Control Panel. For example, the user might choose to display the date in a different format or to use a currency other than the default for the culture.

If CultureInfo.UseUserOverride is true and the specified culture matches the current culture of Windows, the System.Globalization.CultureInfo uses those overrides, including user settings for the properties of the System.Globalization.DateTimeFormatInfo instance returned by the CultureInfo.DateTimeFormat property, and the properties of the System.Globalization.NumberFormatInfo instance returned by the CultureInfo.NumberFormat property. If the user settings are incompatible with the culture associated with the System.Globalization.CultureInfo, for example, if the selected calendar is not one of the CultureInfo.OptionalCalendars, the results of the methods and the values of the properties are undefined.

Namespace: System.Globalization
Assembly: mscorlib (in mscorlib.dll)
Assembly Versions: 1.0.5000.0, 2.0.0.0, 4.0.0.0