uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs,shellapi, StdCtrls,Tlhelp32;

function EnumWindowsProc(hwnd:HWND;lParam:DWORD):boolean; stdcall;
var
szCaption: array[0..256] of Char;
c,h:integer;
begin
    GetWindowText(hwnd,szCaption,127);
    if length(szCaption)>0 then
    begin
      if trim(szCaption)<>'' then
        if pos('qq2009',LowerCase(szCaption))>0 then
         showmessage(inttostr(HWND));
        {GetWindowThreadProcessId(HWND,@c); //这里是窗体名枚举 想判断某个窗体在这里写就成

        if c=FindProcessID('calc.exe') then
           showmessage(inttostr(HWND));

     {if pos('QQ2009',szCaption) >0 then
     begin
     showmessage(szCaption);
     h:=FindWindow(nil,szCaption);
     showmessage(inttostr(h));
     end;}
   end;
    result:=TRUE;
end;

function FindProcessID(s:string):integer;
var
found,find:boolean;
FSnapshotHandle:tHANDLE;
lppe:TProcessEntry32;
begin
FSnapshotHandle := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0); //CreateToolhelp32Snapshot函数得到进程快照
Find:=False;
lppe.dwSize := Sizeof(lppe); //初始化
found := Process32First(FSnapshotHandle, lppe); //Process32First 得到一个系统快照里第一个进程的信息
while found do
    begin
    if LowerCase(ExtractFileName(lppe.szExeFile))=LowerCase(s) then
      begin
      Result:=lppe.th32ProcessID; //找到进程返回ID
      find:=true;
      CloseHandle(FSnapshotHandle);
      exit;
      end;
      found := Process32Next(FSnapshotHandle, lppe);
    end;
CloseHandle(FSnapshotHandle);
if find=False then
Result:=0; //找不到进程返回0
end;

procedure TForm1.Button2Click(Sender: TObject);
begin
EnumWindows(@EnumWindowsProc,0);
end;