copy paste the below code
#include <stdio.h>//yourDialog.cpp file
#include <windows.h>
#include <Wincrypt.h>
#include <iostream>
#include <conio.h>
#include <string>
using namespace std;
#pragma comment(lib, "crypt32.lib")
#define MY_ENCODING_TYPE (PKCS_7_ASN_ENCODING | X509_ASN_ENCODING)
#define KEYLENGTH 0x00800000
PCCERT_CONTEXT pCertContext=NULL;
HANDLE hStoreHandle;
PCERT_PUBLIC_KEY_INFO pOldPubKey = NULL;
char fResponse ='n';
hStoreHandle = CertOpenSystemStore(NULL,"MY");
pCertContext= CertEnumCertificatesInStore(hStoreHandle,pCertContext);
PCERT_INFO pCertifInfo = pCertContext->pCertInfo;
BYTE* pbData = pCertifInfo->SerialNumber.pbData;
DWORD cbData = pCertifInfo->SerialNumber.cbData;
char hex_ascii[3];
CString csAscii;
csAscii.Empty();
if (cbData > 0)
{
int i;
CString cs;
for (i=0; i < cbData; i++)
{
BYTE bb = (BYTE) pbData[i];
sprintf(hex_ascii, "%02X", bb);
cs.Format("%s", hex_ascii);
csAscii = cs + csAscii ;
}
}