When your program displays a dialog box with buttons, please make the buttons match the text. Consider this dialog, which appears after you install patches from Windows Update:
It asks a yes/no question, but the options are "OK" and "Cancel". Either the buttons should be changed to "Yes" and "No", or the text of the message should be changed to match the OK/Cancel buttons. In the latter case, the text could go something like, "Windows Update will restart your computer. If you want to restart later, or close other programs first, click Cancel, and then restart your computer manually."