在一些碰到过的多媒体软件编制过程中通常需要彻底屏蔽任务条，通常的办法是调用ShowWindow(h,SW_hide)来隐藏任务条，但是不能屏蔽开始菜单，通过键盘的win功能键还是可以打开开始菜单，所以配合键盘钩子，来屏蔽开始菜单。

{ Important note about DLL memory management: ShareMem must be the
  first unit in your librarys USES clause AND your projects (select
  Project-View Source) USES clause if your DLL exports any procedures or
  functions that pass strings as parameters or function results. This
  applies to all strings passed to and from your DLL--even those that
  are nested in records and classes. ShareMem is the interface unit to
  the BORLNDMM.DLL shared memory manager, which must be deployed along
  with your DLL. To avoid using BORLNDMM.DLL, pass string information
  using PChar or ShortString parameters. }

uses
  SysUtils,
  Classes,
  windows,
  messages;

var
hHk :HHOOK;
type
  PKBDLLHOOKSTRUCT = ^KBDLLHOOKSTRUCT;
  KBDLLHOOKSTRUCT = record
    vkCode: DWORD;
    ScanCode: DWORD;
    Flags: DWORD;
    Time: DWORD;
    dwExtraInfo: DWORD;
  end;
{$R *.res}
function ycxsks( yc:Boolean): Boolean;stdcall; //隐藏-显示任务条
var
h:THandle;
begin
if yc = True then
  begin
    h:=FindWindow(Shell_TrayWnd,nil);
    ShowWindow(h,SW_hide); //隐藏任务条
  end
else
  begin
    h:=FindWindow(Shell_TrayWnd,nil);
    ShowWindow(h,SW_SHOW); //显示任务条
  end;
Result:=true;
end;

function keyHookProc(nCode: Integer;WParam: WPARAM;LParam: LPARAM): LRESULT;stdcall;
//调用键盘钩子，屏蔽左右win功能键
var
p: PKBDLLHOOKSTRUCT;
y: integer;
begin
if nCode<0 then
  Result:= CallNextHookEx(hHk,nCode,WParam,LParam)
else
  begin
    y := 0;
    case WParam of
    WM_KEYDOWN,WM_SYSKEYDOWN: //按键后判断所按键
      begin
        p:=PKBDLLHOOKSTRUCT(Lparam); 
        if p^.vkCode = VK_LWIN then
          y := 1;
        if p^.vkCode = VK_RWIN then
          y := 1;
      end;
    WM_KEYUP,WM_SYSKEYUP: //松开按键后判断所按键
      begin
        p:=PKBDLLHOOKSTRUCT(Lparam);
        if p^.vkCode = VK_LWIN then
          y := 1;
        if p^.vkCode = VK_RWIN then
          y := 1;
      end;
    end;
    if y=1 then
      Result:=1 //如果为WIN功能键则屏蔽
    else
      Result:= CallNextHookEx(hHk,nCode,WParam,LParam); //其他键放下一个钩子
  end
end;

function Enablehide:Boolean;stdcall;export; //外部调用
begin
if hHk = 0 then
  begin
    hHk := SetWindowsHookEx(13,@keyHookProc,HInstance,0);
    Result := True;
  end
else
  Result := False;
ycxsks(true);
end;

function Disablehide:Boolean; stdcall; export; //外部调用
begin
if hHk <> 0 then
  begin
    UnHookWindowsHookEx(hHk);
    hHk := 0;
    Result := True;
  end
else
  Result := False;
ycxsks(False);
end;

exports
Enablehide,
Disablehide;
end.