Getting real version number of Windows 8.1

Thursday at 09:43 AM3 days

Getting real version number of Windows 8.1:

This doesn't work:
https://gist.github.com/ijat/396663fc902683f9a86be84a7fcd88c5

it returns bogus 5.1 version: 5 major 1 minor


        RtlGetVersionPtr fxPtr = (RtlGetVersionPtr)::GetProcAddress(hMod, "RtlGetVersion");
        if (fxPtr != NULL) {
          rovi.dwOSVersionInfoSize = sizeof(rovi);
          if ( STATUS_SUCCESS == fxPtr(&rovi) ) {
		OSVERSIONINFO os;
        ZeroMemory(&os, sizeof(OSVERSIONINFO));
        os.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
		os.dwMajorVersion = rovi.dwMajorVersion;
		os.dwMinorVersion = rovi.dwMinorVersion;
		int sheetmajor = os.dwMajorVersion;  // 5
		int sheetminor = os.dwMinorVersion;  // 1
		return os;
            }
        }

for Windows 10 I use this and it works:
https://codereview.stackexchange.com/questions/107898/get-os-name-in-c

char* majorv_str = TryReadRegistryKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "CurrentMajorVersionNumber");

char* minorv_str = TryReadRegistryKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "CurrentMinorVersionNumber");

Thursday at 09:59 AM3 days

Author

https://stackoverflow.com/questions/37700605/getting-windows-os-version-programmatically

[HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion]

"CurrentVersion"="6.3"

Problem solved.

1

Thursday at 01:39 PM3 days

Author

Use the reg query command in Command Prompt or PowerShell to display registry values. The basic syntax is reg query "KeyName" /v "ValueName". To see all values under a key, omit /v.

So I've used:

reg query "HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion" /v CurrentVersion
in command prompt return "6.3" proper value but in the program return 5.1 value.
WTF is going on?

Thursday at 02:36 PM3 days

This works as expected for Windows 8.1...

; ***********************************************************************************************************************
;- Global System Libraries
; ***********************************************************************************************************************

Global NtDLL                        = OpenLibrary(#PB_Any, "ntdll.dll")

; ***********************************************************************************************************************
;- Prototypes - NtDLL
; ***********************************************************************************************************************

Prototype.i RtlGetVersion_(dlpVersionInformation)
Global RtlGetVersion_.RtlGetVersion_

RtlGetVersion_ = GetFunction(NtDLL, "RtlGetVersion")

; The RtlGetVersion routine returns version information about the currently running operating system.

Procedure.s GetWindowsVersion()
  Protected RTL.OSVERSIONINFOEX
  
  #STATUS_SUCCESS = #Null
  
  RTL\dwOSVersionInfoSize = SizeOf(RTL)
  
  If RtlGetVersion_
    If RtlGetVersion_(@RTL.OSVERSIONINFOEX) = #STATUS_SUCCESS
      
      OS_dwMajor = RTL\dwMajorVersion
      OS_dwMinor = RTL\dwMinorVersion
      OS_dwBuild = RTL\dwBuildNumber
      
      ProcedureReturn Str(OS_dwMajor) + "." + OS_dwMinor + "." + OS_dwBuild
    EndIf
  EndIf
  
  ProcedureReturn "#NULL"
EndProcedure

Debug GetWindowsVersion()

Ted.

Thursday at 02:55 PM3 days

Author

15 minutes ago, Teddy Rogers said:

This works as expected for Windows 8.1...

; ***********************************************************************************************************************
;- Global System Libraries
; ***********************************************************************************************************************

Global NtDLL                        = OpenLibrary(#PB_Any, "ntdll.dll")

; ***********************************************************************************************************************
;- Prototypes - NtDLL
; ***********************************************************************************************************************

Prototype.i RtlGetVersion_(dlpVersionInformation)
Global RtlGetVersion_.RtlGetVersion_

RtlGetVersion_ = GetFunction(NtDLL, "RtlGetVersion")

; The RtlGetVersion routine returns version information about the currently running operating system.

Procedure.s GetWindowsVersion()
  Protected RTL.OSVERSIONINFOEX
  
  #STATUS_SUCCESS = #Null
  
  RTL\dwOSVersionInfoSize = SizeOf(RTL)
  
  If RtlGetVersion_
    If RtlGetVersion_(@RTL.OSVERSIONINFOEX) = #STATUS_SUCCESS
      
      OS_dwMajor = RTL\dwMajorVersion
      OS_dwMinor = RTL\dwMinorVersion
      OS_dwBuild = RTL\dwBuildNumber
      
      ProcedureReturn Str(OS_dwMajor) + "." + OS_dwMinor + "." + OS_dwBuild
    EndIf
  EndIf
  
  ProcedureReturn "#NULL"
EndProcedure

Debug GetWindowsVersion()

Ted.

Thanks. I think that my Windows 8.1 is corrupted or something,
I can't even find Windows Defender on that Windows,
unfortunately I only have 2 backups of Windows with Windows 8.1.

Thursday at 03:20 PM3 days

Author

Here is my code:
	RTL_OSVERSIONINFOW rovi = { 0 };
    HMODULE hMod = ::GetModuleHandleW(L"ntdll.dll");
    if (hMod)
	{
        RtlGetVersionPtr fxPtr = (RtlGetVersionPtr)::GetProcAddress(hMod, "RtlGetVersion");
        if (fxPtr != NULL)
		{

          rovi.dwOSVersionInfoSize = sizeof(rovi);
          if ( STATUS_SUCCESS == fxPtr(&rovi) )
		  {
		OSVERSIONINFO os;
        ZeroMemory(&os, sizeof(OSVERSIONINFO));
        os.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
		os.dwMajorVersion = rovi.dwMajorVersion;
		os.dwMinorVersion = rovi.dwMinorVersion;

		int sheetmajor = os.dwMajorVersion;  // 5
		int sheetminor = os.dwMinorVersion;  // 1

		return os;
            }
        }
    }

returns v5.1
Here is registry key read:
char* version_str = TryReadRegistryKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "CurrentVersion");

char* TryReadRegistryKey(HKEY hkey,char* regpath, char* valuename)
{
LONG lResult;
HKEY hKey2;
DWORD dwType;
DWORD dwBytes = 100;

lResult = RegOpenKeyEx(hkey, regpath, 0, KEY_READ|KEY_QUERY_VALUE|KEY_WOW64_32KEY, &hKey2);  
if (lResult != ERROR_SUCCESS)   
    return 0;

lResult = RegQueryValueEx(hKey2, valuename, 0, &dwType, (LPBYTE)buffer_keep, &dwBytes);  

RegCloseKey(hKey2);

if (lResult == ERROR_SUCCESS)
return buffer_keep;

return 0;
}

also return v5.1.

@Teddy Rogers I will be very great-full if you post an compiled exe if that is possible.

1

Thursday at 05:45 PM3 days

src & exe ...

GetWinVer_src.zip

Edited Thursday at 06:09 PM3 days by boot

2

Thursday at 10:31 PM3 days

4 hours ago, boot said:
src & exe ...
GetWinVer_src.zip

@boot , I was unable to compile your code for x86 on VS 2022, so I wrote my own based off of what you provided. I was able to compile (x86/x64) and run this code on WIN7+:

// 
// Windows Version Reader by Stingered (2026)
// Compatible: Windows 7 through Windows 11 (hopefully)
//

#include <Windows.h>
#include <stdio.h>
#include <iostream>

typedef NTSTATUS(NTAPI* pfnRtlGetVersion)(PRTL_OSVERSIONINFOW);

void GetRealVersion(DWORD* major, DWORD* minor, DWORD* build, DWORD* revision) {
	HMODULE hMod = GetModuleHandleW(L"ntdll.dll");
	if (hMod) {
		pfnRtlGetVersion RtlGetVersion = (pfnRtlGetVersion)GetProcAddress(hMod, "RtlGetVersion");
		if (RtlGetVersion) {
			OSVERSIONINFOEXW osvi = { 0 };
			osvi.dwOSVersionInfoSize = sizeof(osvi);

			if (RtlGetVersion((PRTL_OSVERSIONINFOW)&osvi) == 0) { // STATUS_SUCCESS
				if (major) *major = osvi.dwMajorVersion;
				if (minor) *minor = osvi.dwMinorVersion;
				if (build) *build = osvi.dwBuildNumber;
			}
		}
	}

	HKEY hKey;
	if (RegOpenKeyExW(HKEY_LOCAL_MACHINE, L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", 0, KEY_QUERY_VALUE, &hKey) == ERROR_SUCCESS) {
		DWORD ubr = 0;
		DWORD size = sizeof(ubr);
		if (RegQueryValueExW(hKey, L"UBR", NULL, NULL, (LPBYTE)&ubr, &size) == ERROR_SUCCESS) {
			if (revision) *revision = ubr;
		}
		RegCloseKey(hKey);
	}
}

int main() {
	std::cout << "\r\n  Windows OS Version Reader\r\n";
	std::cout << "  Compatibility: Windows 7 through Windows 11 (hopefully)\r\n";

	DWORD major = 0;
	DWORD minor = 0;
	DWORD build = 0;
	DWORD revision = 0;

	GetRealVersion(&major, &minor, &build, &revision);

	printf("\r\n  Windows Version -> %u.%u.%u.%u\r\n",
		major,
		minor,
		build,
		revision);

	printf("\n");
	system("pause");
	return 0;
}

Edited Thursday at 10:31 PM3 days by Stingered

1

Saturday at 03:55 AM2 days

Author

char* version_str = TryReadRegistryKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "CurrentVersion");  // CurrentVersion"
if (version_str!=0&&((finded = strstr(version_str,".")) != NULL))

// doesn't work in Windows 8.1 neither on Windows 10.

	RTL_OSVERSIONINFOW rovi = { 0 };
    HMODULE hMod = ::GetModuleHandleW(L"ntdll.dll");
    if (hMod)
	{
        RtlGetVersionPtr fxPtr = (RtlGetVersionPtr)::GetProcAddress(hMod, "RtlGetVersion");
        if (fxPtr != NULL)
		{

          rovi.dwOSVersionInfoSize = sizeof(rovi);
          if ( STATUS_SUCCESS == fxPtr(&rovi) )
		  {
		OSVERSIONINFO os;
        ZeroMemory(&os, sizeof(OSVERSIONINFO));
        os.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
		os.dwMajorVersion = rovi.dwMajorVersion;
		os.dwMinorVersion = rovi.dwMinorVersion;
		return os;
            }
        }
    }

// doesn't work in Windows 8.1 neither on Windows 10.


    PPEB2 pPeb = NtCurrentPeb();

	if (pPeb!=NULL)
	{
	OSVERSIONINFO os;
        ZeroMemory(&os, sizeof(OSVERSIONINFO));
        os.dwOSVersionInfoSize = sizeof(OSVERSIONINFO);
	os.dwMajorVersion = pPeb->OSMajorVersion;
	os.dwMinorVersion = pPeb->OSMinorVersion;
	return os;
	}
// works on all versions of Windows including Windows XP; Windows 8.1, Windows 10, Windows 11.

char* majorv_str = TryReadRegistryKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "CurrentMajorVersionNumber");
// Works on Windows 10 and Windows 11.

So RtlGetVersion doesn't work on Windows 8.1 neither TryReadRegistryKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "CurrentVersion"); "CurrentVersion" seems to be virtualized.

So I will use TryReadRegistryKey(HKEY_LOCAL_MACHINE, "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion", "CurrentMajorVersionNumber"); and if fails PPEB2 pPeb = NtCurrentPeb(); from now.
Thank you @boot

Saturday at 12:31 PM1 day

On 4/9/2026 at 11:20 PM, CodeExplorer said:
I will be very great-full if you post an compiled exe if that is possible.

Apologies for the late response. Let me know if this was not what you wanted...

Ted.

RtlGetVersion.zip

1

Yesterday at 01:16 AM1 day

Author

12 hours ago, Teddy Rogers said:
Apologies for the late response. Let me know if this was not what you wanted...
Ted.
RtlGetVersion.zip

Thanks. Your example works, but in my Visual C++ program RtlGetVersion doesn't work, probability I'm missing some config.
I was able to fix this by @boot samples; all works fine now.

1

Yesterday at 01:43 AM1 day

19 minutes ago, CodeExplorer said:

Thanks. Your example works, but in my Visual C++ program RtlGetVersion doesn't work, probability I'm missing some config.
I was able to fix this by @boot samples; all works fine now.

I didn't try Teddy's, but this method seems to get the same results I had earlier and is supposedly Windows 2000+ (off of stackoverflow). Seems very similar to my earlier code (tiny edits for granularity).

#include <windows.h>
#include <stdio.h>

typedef LONG(WINAPI* RtlGetVersionPtr)(PRTL_OSVERSIONINFOEXW);

DWORD GetUBR()
{
	HKEY hKey;
	DWORD ubr = 0;
	DWORD size = sizeof(ubr);

	if (RegOpenKeyExW(
		HKEY_LOCAL_MACHINE,
		L"SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion",
		0,
		KEY_READ,
		&hKey) == ERROR_SUCCESS)
	{
		RegQueryValueExW(hKey, L"UBR", NULL, NULL, (LPBYTE)&ubr, &size);
		RegCloseKey(hKey);
	}

	return ubr;
}

int main()
{
	HMODULE ntdll = GetModuleHandleW(L"ntdll.dll");
	if (!ntdll) {
		printf("Failed to load ntdll.dll\n");
		return 1;
	}

	RtlGetVersionPtr RtlGetVersion =
		(RtlGetVersionPtr)GetProcAddress(ntdll, "RtlGetVersion");

	if (!RtlGetVersion) {
		printf("RtlGetVersion not found\n");
		return 1;
	}

	RTL_OSVERSIONINFOEXW ver = { 0 };
	ver.dwOSVersionInfoSize = sizeof(ver);

	if (RtlGetVersion(&ver) != 0) {
		printf("RtlGetVersion failed\n");
		return 1;
	}

	DWORD ubr = GetUBR();

	printf("Version: %lu.%lu.%lu.%lu\n",
		ver.dwMajorVersion,
		ver.dwMinorVersion,
		ver.dwBuildNumber,
		ubr
	);

	return 0;
}

Edited yesterday at 01:46 AM1 day by Stingered

Getting real version number of Windows 8.1

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