When the ButtonBase.FlatStyle property of the System.Windows.Forms.RadioButton and System.Windows.Forms.CheckBox classes is set to FlatStyle.System, the control is drawn by the user's operating system and the check alignment is based upon the CheckAlign and ButtonBase.TextAlign property values. The CheckAlign property value is not changed, but the appearance of the control can be affected. The check box is horizontally aligned with either the left or right edge of the control (a left or center alignment appears left aligned, right remains unchanged), and vertically aligned the same as the descriptive text. For example, if you have a System.Windows.Forms.CheckBox control with a CheckAlign property value of System.Drawing.ContentAlignment.MiddleCenter and a ButtonBase.TextAlign property value of System.Drawing.ContentAlignment.TopRight, and the ButtonBase.FlatStyle property value is set to FlatStyle.System, the check box alignment will appear to be System.Drawing.ContentAlignment.TopLeft while the text alignment remains unchanged.

Setting the FlatStyle property to FlatStyle.System is not advisable if you need to display an image on a control, display an image as a control's background, or perform precise text alignment.