Windows Last Boot Date & Time using Delphi - windows

Question

How to get the date & time of the last boot / reboot / restart on Windows 2008/2003 machine?
I know from command prompt we can use "net statistics", but how to do it via Delphi?
Thanks.

Answer 1

You can use the LastBootUpTime property of the Win32_OperatingSystem WMI Class, which return the Date and time the operating system was last restarted (Note : the returned value of this property is in UTC format).
Check this sample app
{$APPTYPE CONSOLE}
uses
SysUtils,
ActiveX,
Variants,
ComObj;
//Universal Time (UTC) format of YYYYMMDDHHMMSS.MMMMMM(+-)OOO.
//20091231000000.000000+000
function UtcToDateTime(const V : OleVariant): TDateTime;
var
Dt : OleVariant;
begin
Result:=0;
if VarIsNull(V) then exit;
Dt:=CreateOleObject('WbemScripting.SWbemDateTime');
Dt.Value := V;
Result:=Dt.GetVarDate;
end;
procedure GetWin32_OperatingSystemInfo;
const
WbemUser ='';
WbemPassword ='';
WbemComputer ='localhost';
wbemFlagForwardOnly = $00000020;
var
FSWbemLocator : OLEVariant;
FWMIService : OLEVariant;
FWbemObjectSet: OLEVariant;
FWbemObject : OLEVariant;
oEnum : IEnumvariant;
iValue : LongWord;
begin;
FSWbemLocator := CreateOleObject('WbemScripting.SWbemLocator');
FWMIService := FSWbemLocator.ConnectServer(WbemComputer, 'root\CIMV2', WbemUser, WbemPassword);
FWbemObjectSet:= FWMIService.ExecQuery('SELECT * FROM Win32_OperatingSystem','WQL',wbemFlagForwardOnly);
oEnum := IUnknown(FWbemObjectSet._NewEnum) as IEnumVariant;
if oEnum.Next(1, FWbemObject, iValue) = 0 then
begin
Writeln(Format('Last BootUp Time %s',[FWbemObject.LastBootUpTime]));// In utc format
Writeln(Format('Last BootUp Time %s',[formatDateTime('dd-mm-yyyy hh:nn:ss',UtcToDateTime(FWbemObject.LastBootUpTime))]));// Datetime
end;
end;
begin
try
CoInitialize(nil);
try
GetWin32_OperatingSystemInfo;
finally
CoUninitialize;
end;
except
on E:Exception do
Writeln(E.Classname, ':', E.Message);
end;
Writeln('Press Enter to exit');
Readln;
end.

Answer 2

Here is a complete command line application that does what you are talking about.
I've modified this to avoid the GetTickCount overflow issues without relying on external function calls.
Example output:
Windows was last rebooted at: 06/29/2011 9:22:47 AM
Have fun!
program lastboottime;
{$APPTYPE CONSOLE}
uses
SysUtils,
Windows;
function UptimeInDays: double;
const
c_SecondsInADay = 86400;
var
cnt, freq: Int64;
begin
QueryPerformanceCounter(cnt);
QueryPerformanceFrequency(freq);
Result := (cnt / freq) / c_SecondsInADay;
end;
function LastBootTime: TDateTime;
begin
Result := Now() - UptimeInDays;
end;
begin
try
WriteLn('Windows was last rebooted at: ' + DateTimeToStr(LastBootTime));
ReadLn;
except on E: Exception do
Writeln(E.ClassName, ': ', E.Message);
end;
end.

Answer 3

Here's a bit of code that uses GetTickCount64 if available and falls back to GetTickCount if unavailable to compute the date and time of system startup. This is not a perfect solution because GetTickCount64 is only supported on Vista+ : if you're on older Windows, the counter goes back to 0 every 49 days.
program Project29;
{$APPTYPE CONSOLE}
uses
SysUtils, Windows;
type
TGetTickCount64 = function : Int64; stdcall;
var
H_K32: HMODULE;
Tick64Proc: TGetTickCount64;
function BootTime: TDateTime;
var UpTime: Int64;
Seconds, Minutes, Hours: Int64;
begin
if H_K32 = 0 then
begin
H_K32 := LoadLibrary(kernel32);
if H_K32 = 0 then
RaiseLastOSError
else
begin
Tick64Proc := GetProcAddress(H_K32, 'GetTickCount64');
end;
end;
if Assigned(Tick64Proc) then
UpTime := Tick64Proc
else
UpTime := GetTickCount;
Result := Now - EncodeTime(0, 0, 0, 1) * UpTime;
end;
begin
WriteLn(DateTimeToStr(BootTime));
ReadLn;
end.

Answer 4

The GetTickCount function (see MSDN) returns the number of milliseconds that have elapsed since the system was started, so divide it with 1000 to get seconds, with 60 000 to get minutes etc.
The topic I linked also contains this bit:
To obtain the time elapsed since the computer was started, retrieve the System Up Time counter in the performance data in the registry key HKEY_PERFORMANCE_DATA. The value returned is an 8-byte value. For more information, see Performance Counters.