How do I change the default Windows printer?

You need to change the printer, driver, and port as listed in thedevice key of the Windows section in the Win.ini file, thenbroadcast a system wide WM_WININICHANGE message.


Example:

uses
   IniFiles;

procedure TForm1.Button1Click(Sender: TObject);
var
   WinIni : TIniFile;
   WinIniFileName : array[0..MAX_PATH] of char;
   s : array[0..64] of char;

begin
   GetWindowsDirectory(WinIniFileName, sizeof(WinIniFileName));
   StrCat(WinIniFileName, '\win.ini');
   WinIni := TIniFile.Create(WinIniFileName);
   try
     WinIni.WriteString('windows',
                        'device',
                        'HP LaserJet Series II,HPPCL,LPT1:');
   finally
     WinIni.Free;
   end;

   StrCopy(S, 'windows');
   SendMessage(HWND_BROADCAST, WM_WININICHANGE, 0, LongInt(@S));