Unique CPU ID on Windows via C++

Well I would like to get an unique CPU ID so I can get an UNIQUE identification for each machine.
I did check __cpuid() from windows.h library, but the problem is that the ID it gets, it's the ID of all types of CPU, if you have an I3 Core processor and I have an I3 core processor, it will give the same "Unique ID".

Here is what I came up with to make a CPU ID from the __cpuid() that returns the same information on processors of the same type:

std::string GetCPUID(){
 
             int CPUInfo[4] = {-1};
             __cpuid(CPUInfo, 0);
              if (CPUInfo[0] < 4)
             return ""; //Error on retrieving
 
             stringstream st;
             for(int i = 0; i <= 3; i++){ 
                          st << CPUInfo[i];
                     }
 
             return st.str();
 
 }
 

I also checked a program called "Hardware ID Extractor" that works fine, it actually returns a UNIQUE CPU ID as the GUI as I wanted, so they made available a DLL so we can extract the CPU ID it generated , I tried everything with the cleanest code with the DLL and following their example but it seems that it returns nothing when ran on Windows 7. a lot of other people were complaining about this on Windows 7 via the DLL, even though the GUI on windows 7 returns the correct CPU ID.

Showing my work in the Hardware ID Extractor,

Here is the site where I downloaded the DLL (Where I chose the link of C++, VB, .NET): http://www.soft.tahionic.com/download-hdd_id/free-download/free%20download.html

And here is the DLL itself to download: http://www.soft.tahionic.com/download-hdd_id/free-download/DLL%20compressed/HardwareIDExtractorC.dll

This is the code I got from Hardware ID Extractor (I'm using Visual Studio 2008):

#include <iostream>
 #include <windows.h>
 #include <conio.h>
 using namespace std;
 
 int main (){
 
     char* (__stdcall *GetIDESerialNumber)(BYTE);
 
     HINSTANCE DllInst = NULL;
     if (DllInst == NULL) DllInst = LoadLibrary("C:\\HardwareIDExtractorC.dll");
     if (DllInst) {
         GetIDESerialNumber = (char* (__stdcall*)(BYTE))GetProcAddress(DllInst, "GetIDESerialNumber");
 
     //Now call the imported function
         cout << "SN: " <<  GetIDESerialNumber(0);   // 0 = first IDE hard drive in your system 
     }else{
         printf("Not Loaded");
     }
 
     _getch();
 
 
 
 return 0;
 }
 

In the visual studio output it shows that the DLL was executed by saying:

'Test.exe': Loaded 'C:\HardwareIDExtractorC.dll', Binary was not built with debug information.
 

And the program output that I get is: Not loaded

Someone know what I can do to get a CPU ID Unique, like in the application Hardware ID Extractor? I need to get a CPU ID because if I get HDD information, the user may format their Hard Drive and the program will stop working, as I'm designing it to work only that specified computer.

I'm using Windows 7 32 bits Ultimate and Intel I3 Core Processor (if that helps in anyway).

I hope I was clear in my question.
Thanks in advance!

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