Советы по Delphi. Версия 1.4.3 от 1.1.2001

 While Child <> 0 do Begin
 If GetClassName(Child, C, SizeOf(C)) > 0 Then Begin
 S := StrPAS(C);
 If UpperCase(S) = 'BUTTON' then begin
 If Visi then ShowWindow(Child, 1)
 else ShowWindow(Child, 0);
 end;
 End;
 Child := GetWindow(Child, GW_HWNDNEXT);
 End;
End;

//убрать/показать TaskBar
procedure TaskBar(visi:boolean);
begin
if visi then ShowWindow(FindWindow('Shell_TrayWnd', nil), SW_SHOW) // Показать Taskbar
 else ShowWindow(FindWindow('Shell_TrayWnd', nil), SW_HIDE); //Скрыть TaskBar
end;

procedure applicationInCtrlAltDelList(visi:boolean);
begin
 if visi then begin
 //Show
 RegisterServiceProcess(GetCurrentProcessID, 0);
 end else begin
 //Hide
 RegisterServiceProcess(GetCurrentProcessID, 1);
 end;
end;

procedure applicationInTaskBar(visi:boolean);
begin
 if visi then windows.ShowWindow(FindWindow(nil, @Application.Title[1]), SW_SHOW)
 else windows.ShowWindow(FindWindow(nil, @Application.Title[1]), SW_HIDE);
end;

procedure RussianKbdLayout;//На русский
var Layout: array[0..KL_NAMELENGTH] of char;
begin
 LoadKeyboardLayout(StrCopy(Layout, '00000419'), KLF_ACTIVATE);
end;

procedure EnglishKbdLayout;//На английский
var Layout: array[0..KL_NAMELENGTH] of char;
begin
 LoadKeyboardLayout(StrCopy(Layout, '00000409'), KLF_ACTIVATE);
end;

procedure UkrainianKbdLayout;//На украинский
var Layout: array[0..KL_NAMELENGTH] of char;
begin
 LoadKeyboardLayout(StrCopy(Layout, pChar(intToHex(LANG_UKRAINIAN+$400, 8))), KLF_ACTIVATE);
end;

//запустить текущий ScreenSaver
procedure RunCurrentScreenSaver;
begin
 SendMessage(Application.Handle, WM_SYSCOMMAND, SC_SCREENSAVE, 0);
end;

//очистить меню "Документы"
procedure clearDocuments;
begin
 SHAddToRecentDocs(SHARD_PATH, nil);
end;

//добавить документ в меню 'Документы'
// Для данного файла должно быть зарегистрировано средство просмотра
procedure addFileToDocuments(const fileName:string);
begin
 SHAddToRecentDocs(SHARD_PATH, pchar(fileName));
end;

//Значение функции TRUE если мелкий шрифт
function SmallFonts:Boolean;
var DC:HDC;
begin
 DC:=GetDC(0);
 Result:=(GetDeviceCaps(DC, LOGPIXELSX) = 96);
 { В случае крупного шрифта будет 120}
 ReleaseDC(0, DC);
end;

function DriveExists(Drive : Byte) : Boolean;
begin
 Result := Boolean(GetLogicalDrives AND (1 SHL Drive))
end;

//'?';'Path does not exists';'Removable';'Fixed';'Remote';'CD-ROM';'RAMDISK'
function CheckDriveType(Drive : Byte) : String;
var
 DriveLetter : Char;
 DriveType : UInt;
begin
 DriveLetter := Char(Drive + $41);
 DriveType := GetDriveType(PChar(DriveLetter + ':\'));
 Case DriveType of
 0 : Result := '?';
 1 : Result := 'Path does not exists';
 DRIVE_REMOVABLE : Result := 'Removable';