Author: Jonas Bilinkevicius 

I am trying to build a component to get info about the programs executing in my NT4 
environment. I managed to get the names for all the windows running (title text). 
Now, how can I get the process ID for each of them? Which function should I use? Is 
there any function that tells me for how long my process is running?

Answer:

It is better to use the EnumWindows function instead of FindWindow/GetWindow, 
because the latter isn't sensitive to windows being destroyed halfway through the 
loop and you can end up getting invalid handles. Here's an example:
1   
2   function EnumWindowsProc(hWnd: LongWord; Form: TForm1): WordBool; stdcall;
3   begin
4     Form.FoundAWindow(hWnd);
5     Result := True
6   end;
7   
8   procedure TForm1.FoundAWindow(hWnd: LongWord);
9   var
10    ProcessID: LongWord;
11    Title: array[0..255] of Char;
12  begin
13    GetWindowThreadProcessID(hWnd, @ProcessID);
14    GetWindowText(hWnd, Title, 256);
15    {Now, do whatever you want with Title and ProcessID, e.g.:}
16    Memo1.Lines.Add(Title + ' [' + IntToStr(ProcessID) + ']')
17  end;
18  
19  procedure TForm1.Timer1Timer(Sender: TObject);
20  begin
21    EnumWindows(@EnumWindowsProc, Integer(Self))
22  end;