Hola, en Trucomania he encontrado esta función no se si te servirá.
Código Delphi
[-]function Uptime: string;
var count, days, min, hours, seconds : longint;
begin
Count := GetTickCount();
Count := Count div 1000;
Days := Count div (24 * 3600);
if Days > 0 then
Count := Count - (24 * 3600 * Days);
Hours := Count div 3600;
If Hours > 0 Then
Count := Count - (3600 * Hours);
Min := Count div 60;
Seconds := Count Mod 60;
Result := IntToStr(Days)+' Days '+IntToStr(Hours)+
' hours '+IntToStr(Min)+' minutes '+
IntToStr(seconds) +' seconds ';
end;
Saludos