Author: Fernando Silva 

How to get Windows uptime?

Answer:

Use the following function:

1   function UpTime: string;
2   const
3     ticksperday: integer = 1000 * 60 * 60 * 24;
4     ticksperhour: integer = 1000 * 60 * 60;
5     ticksperminute: integer = 1000 * 60;
6     tickspersecond: integer = 1000;
7   
8   var
9     t: longword;
10    d, h, m, s: integer;
11  
12  begin
13    t := GetTickCount;
14  
15    d := t div ticksperday;
16    dec(t, d * ticksperday);
17  
18    h := t div ticksperhour;
19    dec(t, h * ticksperhour);
20  
21    m := t div ticksperminute;
22    dec(t, m * ticksperminute);
23  
24    s := t div tickspersecond;
25  
26    Result := 'Uptime: ' + IntToStr(d) + ' Days ' + IntToStr(h) + ' Hours ' + 
27  IntToStr(m)
28      + ' Minutes ' + IntToStr(s) + ' Seconds';
29  end;