var
  sAppDir: string;
  bLoadedFont: boolean;
 
procedure TForm1.FormCreate(Sender: TObject);
var
  sFontRes, sFont: string;
begin
 sAppDir:=ExtractFileDir(Application.ExeName);
 sFontRes:=sAppDir+'MYFONT.FOT';
 if not FileExists(sFontRes) then
  begin
   sFontRes:=sFontRes+#0;
   sFont:=sAppDir+'MYFONT.TTF'+#0;
   CreateScalableFontResource(0, @sFontRes[1], @sFont[1], nil);
  end;
 
 sFontRes:=sAppDir+'MYFONT.FOT';
 if FileExists(sFontRes) then
  begin
   sFontRes:=sFontRes+#0;
   if AddFontResource(@sFontRes[1])=0 then
    bLoadedFont:=False
   else
    begin
     bLoadedFont:=True;
     SendMessage(HWND_BROADCAST, WM_FONTCHANGE, 0, 0);
    end;
  end;
end;
 
procedure TForm1.FormDestroy(Sender: TObject);
var
 sFontRes: string;
begin
 if bLoadedFont then
  begin
   sFontRes:=sAppDir+'MYFONT.FOT'+#0;
   RemoveFontResource(@sFontRes[1]);
   SendMessage(HWND_BROADCAST, WM_FONTCHANGE, 0, 0);
  end;
end;