Sometimes you may want to find out if the user has "Full Windows Dragging" enabled.

Full Windows dragging means that the contents of a Window is visible, while the user is dragging it. If  full Windows dragging isn't enabled only the outline of the Window is visible.

You can use the following function to determined whether full Windows dragging is enabled or not.

function FullWindowDragging : boolean;

begin
  if (WindowsExtensionInstalled) then
    SystemParametersInfo(SPI_GETDRAGFULLWINDOWS, 0, @Result, 0)
  else
    Messagedlg('FullWindowDragging - Error: Windows Plus must be installed!', mterror, [mbok], 0);
end;

This function will return TRUE if enabled or FALSE, otherwise.

NOTE:

For this function to work the user must have Windows Plus installed on his/her's Windows'95 machine.
Windows'98 users do not need to worry, because Windows Plus is available with the Windows'98 package.

The function uses the WindowsExtensionInstalled-function to determine whether Windows Plus is installed.
It will display an error if not.

For more information on the WindowsExtensionInstalled-function read my tip
"Is Windows Extension (Windows Plus) Installed?"