{******************************************************************************}
{**                                                                          **} 
{** ProzessID an Hand der Exe-Datei ermittlen                                **} 
{**                                                                          **} 
{******************************************************************************} 
function GetProcessID(sProcName: String): Integer;
var
  hProcSnap: THandle;
  pe32: TProcessEntry32;
begin
  result := -1;
  hProcSnap := CreateToolHelp32SnapShot(TH32CS_SNAPPROCESS, 0);
  if hProcSnap = INVALID_HANDLE_VALUE then exit;

  pe32.dwSize := SizeOf(ProcessEntry32);

  { wenn es geklappt hat } 
  if Process32First(hProcSnap, pe32) = true then
    { und los geht's: Prozess suchen} 
    while Process32Next(hProcSnap, pe32) = true do
    begin
      if pos(sProcName, pe32.szExeFile) <> 0then
        result := pe32.th32ProcessID;
    end;
CloseHandle(hProcSnap);
end;

{******************************************************************************}
{**                                                                          **}
{** Prozess beenden                                                          **}
{**                                                                          **}
{******************************************************************************}
procedure KillProcess(dwProcID: DWORD);
var
  hProcess : Cardinal;
  dw : DWORD;
begin
  { open the process and store the process-handle }
  hProcess := OpenProcess(SYNCHRONIZE or PROCESS_TERMINATE, False, dwProcID);
  { kill it }
  TerminateProcess(hProcess, 0);
  { TerminateProcess returns immediately, so wie have to verify the result via
    WaitfForSingleObject }
  dw := WaitForSingleObject(hProcess, 5000);
  case dw of
    { everythings's all right, we killed the process } 
    WAIT_OBJECT_0: Messagebox(Application.Handle, 'Prozess wurde beendet.', 'Prozess beenden',
      MB_ICONINFORMATION);
    { process could not be terminated after 5 seconds } 
    WAIT_TIMEOUT:
    begin
      Messagebox(Application.Handle, 'Prozess konnte nicht innerhalb von 5 Sekunden beendet werden.',
        'Prozess beenden', MB_ICONSTOP);
      CloseHandle(hProcess);
      exit;
    end;
    { error in calling WaitForSingleObject }
    WAIT_FAILED:
    begin
      RaiseLastOSError;
      CloseHandle(hProcess);
      exit;
    end;
  end;
  CloseHandle(hProcess);
  end;

procedure TForm1.Button1Click(Sender: TObject);
begin
    KillProcess(GetProcessID(edit1.text)); // in edit1 muss zb icq.exe stehen
end;