Programmatically Check if Windows is Activated with C++ - c++

Question

I am trying to write a C++ function that will tell the user if the windows OS they are currently using is activated of not.
I found a similar question Programmatically check if Windows 7 is activated , but this answer requires a UID argument. I DO NOT want the user to have to enter ANY arguments at all.
How do I programmatically Check if Windows is Activated with C++?

Answer 1

#define _WIN32_WINNT 0x600
#include <iostream>
#include <windows.h>
#include <slpublic.h>
/*'
From: C:/Windows/System32/SLMGR.vbs
' Copyright (c) Microsoft Corporation. All rights reserved.
'
' Windows Software Licensing Management Tool.
'
' Script Name: slmgr.vbs
'
' WMI class names
private const ServiceClass = "SoftwareLicensingService"
private const ProductClass = "SoftwareLicensingProduct"
private const TkaLicenseClass = "SoftwareLicensingTokenActivationLicense"
private const WindowsAppId = "55c92734-d682-4d71-983e-d6ec3f16059f"
*/
/** Use the WindowsAppId above to check if Windows OS itself is Genuine. **/
bool isGenuineWindows()
{
//WindowsAppId
unsigned char uuid_bytes[] = {0x35, 0x35, 0x63, 0x39, 0x32, 0x37, 0x33, 0x34, 0x2d, 0x64, 0x36,
0x38, 0x32, 0x2d, 0x34, 0x64, 0x37, 0x31, 0x2d, 0x39, 0x38, 0x33,
0x65, 0x2d, 0x64, 0x36, 0x65, 0x63, 0x33, 0x66, 0x31, 0x36, 0x30,
0x35, 0x39, 0x66};
GUID uuid;
SL_GENUINE_STATE state;
UuidFromStringA(uuid_bytes, &uuid);
SLIsGenuineLocal(&uuid, &state, nullptr);
return state == SL_GEN_STATE_IS_GENUINE;
}
int main()
{
std::cout<<isGenuineWindows();
return 0;
}
Link against: librpcrt4.a and libslwga.a

Answer 2

For some reason, the accepted answer failed on me. It's always returning false. I'll leave the code below for future purposes. It worked for me starting from Windows-Vista and, as of now Windows-10 version 20H2.
#define _WIN32_WINNT 0x600
#include <iostream>
#include <windows.h>
#include <slpublic.h>
#include <tchar.h>
#pragma comment(lib, "Slwga.lib")
#pragma comment(lib, "Rpcrt4.lib")
using std::cout;
using std::endl;
bool isGenuineWindows()
{
GUID uid;
RPC_WSTR rpc = (RPC_WSTR)_T("55c92734-d682-4d71-983e-d6ec3f16059f");
UuidFromString(rpc, &uid);
SL_GENUINE_STATE state;
SLIsGenuineLocal(&uid, &state, NULL);
return state == SL_GEN_STATE_IS_GENUINE;
}
int main()
{
if (isGenuineWindows()) {
cout << "Licensed" << endl;
}
else {
cout << "Unlicensed" << endl;
}
return 0;
}