WMI with delphi - delphi

Question

I've been working on a project which would read the temperature of the CPU.
Unfortunately I'm getting a conversion error. The whole thing compiles without a problem. But when I actually try to execute the code it gives me this error:
"Could not convert variant of type (Dispatch) into type (String)"
I'm not actually trying to get the Temp, On this bit I'm just looking if the way this is coded works. Temp part is going to be added later on...
The particular code:
unit Unit3;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs, Menus, ExtCtrls, jpeg, WbemScripting_TLB, StdCtrls;
type
TForm3 = class(TForm)
MainMenu1: TMainMenu;
F1: TMenuItem;
Quit1: TMenuItem;
Help1: TMenuItem;
Programms1: TMenuItem;
CalCulator1: TMenuItem;
Browser1: TMenuItem;
emperature1: TMenuItem;
WallPad1: TMenuItem;
MediaPlayer1: TMenuItem;
Image1: TImage;
Image2: TImage;
Load1: TMenuItem;
Background1: TMenuItem;
Label1: TLabel;
Button1: TButton;
procedure CalCulator1Click(Sender: TObject);
procedure Image1DblClick(Sender: TObject);
procedure Browser1Click(Sender: TObject);
procedure FormCreate(Sender: TObject);
procedure MediaPlayer1Click(Sender: TObject);
procedure Button1Click(Sender: TObject);
private
{ Private declarations }
public
{ Public declarations }
end;
var
Form3: TForm3;
WMIServices: ISWbemServices;
Root : ISWbemObjectSet;
Item : Variant;
I : Integer;
implementation
uses Unit4, Unit2, Unit5;
{$R *.dfm}
procedure TForm3.Browser1Click(Sender: TObject);
begin
Form2.Show;
end;
procedure TForm3.Button1Click(Sender: TObject);
begin
WMIServices := CoSWbemLocator.Create.ConnectServer('.', 'root\cimv2','', '', '', '', 0, nil);
Root := WMIServices.ExecQuery('Select DeviceID FROM Win32_TemperatureProbe','WQL', 0, nil);
Label1.caption := VarToStr(Root)
end;
procedure TForm3.CalCulator1Click(Sender: TObject);
begin
form4.show;
end;
procedure TForm3.FormCreate(Sender: TObject);
begin
image1.bringtofront
end;
procedure TForm3.Image1DblClick(Sender: TObject);
begin
Form4.show;
end;
procedure TForm3.MediaPlayer1Click(Sender: TObject);
begin
form5.show;
end;
end.
I'm assuming the solution is going to be quite simple, yet I can't see it...
The error is created on this bit
Label1.caption := VarToStr(Root)

Answer 1

Before continuing on this path maybe you should read the documentation Win32_TemperatureProbe class.
In the header you can read:
"Most of the information That the Win32_TemperatureProbe WMI class Provides you eat from SMBIOS. Real-time readings for the CurrentReading property can not be Retrieved from SMBIOS tables. For this reason, current implementations of WMI do not populate the CurrentReading property. The CurrentReading property's Presence is reserved for future use."
if you want to use WMI correctly, you can find much information on the website of Rodrigo Ruz or on my website including samples and specific components to WMI (GLibWMI on Sourceforge).
There is an interesting project (opensource) in http://openhardwaremonitor.org to access hardware properties (including the ones you need). Check it out.
A greeting.