diff --git a/dll/ntdll/def/ntdll.spec b/dll/ntdll/def/ntdll.spec
index 793c3bb58da..033b8b434ae 100644
--- a/dll/ntdll/def/ntdll.spec
+++ b/dll/ntdll/def/ntdll.spec
@@ -902,7 +902,7 @@
 @ stdcall RtlGetOwnerSecurityDescriptor(ptr ptr ptr)
 @ stdcall -stub -version=0x600+ RtlGetParentLocaleName(wstr long long long)
 @ stdcall RtlGetProcessHeaps(long ptr)
-@ stub -version=0x600+ RtlGetProductInfo
+@ stdcall -version=0x600+ RtlGetProductInfo(long long long long ptr)
 @ stdcall RtlGetSaclSecurityDescriptor(ptr ptr ptr ptr)
 @ stdcall RtlGetSecurityDescriptorRMControl(ptr ptr)
 @ stdcall RtlGetSetBootStatusData(ptr long long ptr long long)
diff --git a/dll/ntdll/nt_0600/ntdll_vista.spec b/dll/ntdll/nt_0600/ntdll_vista.spec
index 2eaebb54fcc..1b4072f2459 100644
--- a/dll/ntdll/nt_0600/ntdll_vista.spec
+++ b/dll/ntdll/nt_0600/ntdll_vista.spec
@@ -1,6 +1,7 @@
 @ stdcall LdrRegisterDllNotification(long ptr ptr ptr)
 @ stdcall LdrUnregisterDllNotification(ptr)
 
+@ stdcall RtlGetProductInfo(long long long long ptr)
 @ stdcall RtlInitializeConditionVariable(ptr)
 @ stdcall RtlWakeConditionVariable(ptr)
 @ stdcall RtlWakeAllConditionVariable(ptr)
diff --git a/dll/win32/kernel32/kernel32.spec b/dll/win32/kernel32/kernel32.spec
index ecd51f8447e..b89a28d9624 100644
--- a/dll/win32/kernel32/kernel32.spec
+++ b/dll/win32/kernel32/kernel32.spec
@@ -574,7 +574,7 @@
 @ stdcall GetProcessVersion(long)
 @ stdcall GetProcessWorkingSetSize(long ptr ptr)
 @ stdcall GetProcessWorkingSetSizeEx(long ptr ptr long)
-@ stub -version=0x600+ GetProductInfo
+@ stdcall -version=0x600+ GetProductInfo(long long long long ptr) ntdll.RtlGetProductInfo
 @ stdcall GetProfileIntA(str str long)
 @ stdcall GetProfileIntW(wstr wstr long)
 @ stdcall GetProfileSectionA(str ptr long)
diff --git a/dll/win32/kernel32/kernel32_vista/kernel32_vista.spec b/dll/win32/kernel32/kernel32_vista/kernel32_vista.spec
index 58f2dc492f0..dd2eb0b9fec 100644
--- a/dll/win32/kernel32/kernel32_vista/kernel32_vista.spec
+++ b/dll/win32/kernel32/kernel32_vista/kernel32_vista.spec
@@ -65,3 +65,4 @@
 @ stdcall GetSystemTimePreciseAsFileTime(ptr) kernel32.GetSystemTimeAsFileTime
 @ stdcall TrySubmitThreadpoolCallback(ptr ptr ptr)
 @ stdcall FreeLibraryWhenCallbackReturns(ptr ptr) ntdll_vista.TpCallbackUnloadDllOnCompletion
+@ stdcall GetProductInfo(long long long long ptr) ntdll_vista.RtlGetProductInfo
diff --git a/sdk/lib/rtl/CMakeLists.txt b/sdk/lib/rtl/CMakeLists.txt
index c6afb4c3e0c..3a4ba08dbbb 100644
--- a/sdk/lib/rtl/CMakeLists.txt
+++ b/sdk/lib/rtl/CMakeLists.txt
@@ -19,6 +19,7 @@ list(APPEND RTL_WINE_SOURCE
     threadpool.c
 )
 list(APPEND RTL_WINE_SOURCE_VISTA
+    product.c
     threadpool.c
 )
 set_source_files_properties(threadpool.c PROPERTIES COMPILE_DEFINITIONS __WINESRC__)
diff --git a/sdk/lib/rtl/product.c b/sdk/lib/rtl/product.c
new file mode 100644
index 00000000000..98ff5808da3
--- /dev/null
+++ b/sdk/lib/rtl/product.c
@@ -0,0 +1,62 @@
+/*
+ * PROJECT:     ReactOS runtime library (RTL)
+ * LICENSE:     MIT (https://spdx.org/licenses/MIT)
+ * PURPOSE:     Implementation of RtlGetProductInfo
+ * COPYRIGHT:   Copyright 2026 Timo Kreuzer <timo.kreuzer@reactos.org>
+ */
+
+/* INCLUDES *****************************************************************/
+
+#include <rtl.h>
+
+#define NDEBUG
+#include <debug.h>
+
+BOOLEAN
+WINAPI
+RtlGetProductInfo(
+    _In_ ULONG OSMajorVersion,
+    _In_ ULONG OSMinorVersion,
+    _In_ ULONG SpMajorVersion,
+    _In_ ULONG SpMinorVersion,
+    _Out_ PULONG ReturnedProductType)
+{
+    if (ReturnedProductType == NULL)
+    {
+        return FALSE;
+    }
+
+    if (OSMajorVersion < 6)
+    {
+        *ReturnedProductType = PRODUCT_UNDEFINED;
+        return FALSE;
+    }
+
+    if (SharedUserData->NtProductType == NtProductWinNt)
+    {
+        if ((OSMajorVersion == 6) && (OSMinorVersion == 0))
+        {
+            *ReturnedProductType = PRODUCT_BUSINESS;
+        }
+        else
+        {
+            *ReturnedProductType = PRODUCT_PROFESSIONAL;
+        }
+        return TRUE;
+    }
+    else if (SharedUserData->NtProductType == NtProductLanManNt)
+    {
+        *ReturnedProductType = PRODUCT_ENTERPRISE_SERVER;
+        return TRUE;
+    }
+    else if (SharedUserData->NtProductType == NtProductServer)
+    {
+        *ReturnedProductType = PRODUCT_STANDARD_SERVER;
+        return TRUE;
+    }
+
+    *ReturnedProductType = PRODUCT_UNDEFINED;
+    return FALSE;
+}
+
+/* EOF */