Wie installations datum von windows ermittlen ?

[NicoDE]

Nachtrag für Win9x (ab Win95, erste Version, ohne Updates)

Delphi-Quellcode:

function GetWindowsInstallDateTime: TDateTime;
const
  RegKeyNT = 'SOFTWARE\Microsoft\Windows NT\CurrentVersion';
  RegValNT = 'InstallDate';
  RegKey95 = 'SOFTWARE\Microsoft\Windows\CurrentVersion';
  RegVal95 = 'FirstInstallDateTime';
  function RegReadDWORD(const Key, Name: string): DWORD;
  begin
    Result := 0;
    with TRegistry.Create do
      try
        RootKey := HKEY_LOCAL_MACHINE;
        if KeyExists(Key) and OpenKeyReadOnly(Key) and ValueExists(Name) and
          (GetDataType(Name) in [rdInteger, rdBinary, rdUnknown]) and
          (GetDataSize(Name) = SizeOf(Result)) then
          if GetDataType(Name) = rdInteger then
            Result := DWORD(ReadInteger(Name))
          else
            ReadBinaryData(Name, Result, SizeOf(Result));
      finally
        Free;
      end;
  end;
var
  Value: DWORD;
begin
  Value := RegReadDWORD(RegKeyNT, RegValNT);
  if Value <> 0 then
    Result := EncodeDate(1970, 1, 1) + (Value / SecsPerDay)
  else
  begin
    Value := RegReadDWORD(RegKey95, RegVal95);
    if Value <> 0 then
      Result := FileDateToDateTime(Value)
    else
      Result := 0.0;
  end;
end;

////////////////////////////////////////////////////////////////////////////////
// Beispiel

procedure TForm1.Button1Click(Sender: TObject);
begin
  ShowMessage(FormatDateTime('yyyy-mm-dd hh:nn:ss', GetWindowsInstallDateTime));
end;

Viel Spass