About Dialog OS Version

src/cascadia/TerminalApp/Resources/en-US/Resources.resw

@@ -166,7 +166,7 @@ Temporarily using the Windows Terminal default settings.
     <value>About</value>
   </data>
   <data name="VersionLabelText" xml:space="preserve">
-    <value>Version:</value>
+    <value>WT Version:</value>
   </data>
   <data name="DocumentationLabelText" xml:space="preserve">
     <value>Documentation
@@ -210,4 +210,7 @@ Temporarily using the Windows Terminal default settings.
   <data name="CloseWindowWarningTitle" xml:space="preserve">
     <value>Do you want to close all tabs?</value>
   </data>
+  <data name="OsVersionLabelText" xml:space="preserve">
+    <value>OS Version:</value>
+  </data>
 </root>

src/cascadia/TerminalApp/TerminalPage.cpp

@@ -153,6 +153,57 @@ namespace winrt::TerminalApp::implementation
         _showDialogHandlers(*this, dialog);
     }
 
+    // Method Description:
+    // - Implements the MSDN suggested method of obtaining the full OS version number
+    //   https://docs.microsoft.com/en-us/windows/win32/sysinfo/getting-the-system-version
+    // - On failure the output wstring will be L"0.0.0.0"
+    std::wstring TerminalPage::_GetWindowsVersion()
+    {
+        const auto dll{ L"KernelBase.dll" };
+        DWORD fill{};
+        const auto infoSize{ GetFileVersionInfoSizeExW(FILE_VER_GET_NEUTRAL, dll, &fill) };
+        auto buffer{ wil::make_unique_nothrow<BYTE[]>(infoSize) };
+        // clear variables for use in case of failure
+        WORD osMaj{}, osMin{}, osBld{}, osRev{};
+
+        if (GetFileVersionInfoExW(FILE_VER_GET_NEUTRAL, dll, fill, infoSize, buffer.get()))
+        {
+            VS_FIXEDFILEINFO* versionInfo{ nullptr };
+            UINT size{};
+
+            if (VerQueryValueW(buffer.get(), L"\\", (LPVOID*)&versionInfo, &size))
+            {
+                osMaj = HIWORD(versionInfo->dwProductVersionMS);
+                osMin = LOWORD(versionInfo->dwProductVersionMS);
+                osBld = HIWORD(versionInfo->dwProductVersionLS);
+                osRev = LOWORD(versionInfo->dwProductVersionLS);
+            }
+        }
+
+        SYSTEM_INFO sysInfo{};
+        std::wstring arch{ L"Unknown" };
+        GetSystemInfo(&sysInfo);
+
+        switch (sysInfo.wProcessorArchitecture)
+        {
+        case PROCESSOR_ARCHITECTURE_AMD64:
+            arch = L"x64";
+            break;
+        case PROCESSOR_ARCHITECTURE_ARM64:
+            arch = L"ARM64";
+            break;
+        case PROCESSOR_ARCHITECTURE_INTEL:
+            arch = L"x86";
+            break;
+        default:
+            break;
+        }
+
+        std::wstringstream osVersionStream{};
+        osVersionStream << osMaj << L"." << osMin << L"." << osBld << L"." << osRev << L" " << arch;
+        return osVersionStream.str();
+    }
+
     // Method Description:
     // - Show a dialog with "About" information. Displays the app's Display
     //   Name, version, getting started link, documentation link, and release
@@ -161,6 +212,7 @@ namespace winrt::TerminalApp::implementation
     {
         const auto title = RS_(L"AboutTitleText");
         const auto versionLabel = RS_(L"VersionLabelText");
+        const auto osVersionLabel = RS_(L"OsVersionLabelText");
         const auto gettingStartedLabel = RS_(L"GettingStartedLabelText");
         const auto documentationLabel = RS_(L"DocumentationLabelText");
         const auto releaseNotesLabel = RS_(L"ReleaseNotesLabelText");
@@ -170,6 +222,8 @@ namespace winrt::TerminalApp::implementation
         const auto package = winrt::Windows::ApplicationModel::Package::Current();
         const auto packageName = package.DisplayName();
         const auto version = package.Id().Version();
+        const auto osVersion = _GetWindowsVersion();
+
         winrt::Windows::UI::Xaml::Documents::Run about;
         winrt::Windows::UI::Xaml::Documents::Run gettingStarted;
         winrt::Windows::UI::Xaml::Documents::Run documentation;
@@ -197,7 +251,8 @@ namespace winrt::TerminalApp::implementation
 
         // Format our about text. It will look like the following:
         // <Display Name>
-        // Version: <Major>.<Minor>.<Build>.<Revision>
+        // WT Version: <WtMajor>.<WtMinor>.<WtBuild>.<WtRevision>
+        // OS Version: <OsMajor>.<OsMinor>.<OsBuild>.<OsRevision> <CpuArch>
         // Getting Started
         // Documentation
         // Release Notes
@@ -207,6 +262,8 @@ namespace winrt::TerminalApp::implementation
         aboutTextStream << versionLabel.c_str() << L" ";
         aboutTextStream << version.Major << L"." << version.Minor << L"." << version.Build << L"." << version.Revision << L"\n";
 
+        aboutTextStream << osVersionLabel.c_str() << L" " << osVersion.c_str() << L"\n";
+
         winrt::hstring aboutText{ aboutTextStream.str() };
         about.Text(aboutText);
 

src/cascadia/TerminalApp/TerminalPage.h

@@ -68,6 +68,8 @@ namespace winrt::TerminalApp::implementation
         std::optional<int> _rearrangeFrom;
         std::optional<int> _rearrangeTo;
 
+        std::wstring _GetWindowsVersion();
+
         winrt::com_ptr<ShortcutActionDispatch> _actionDispatch{ winrt::make_self<ShortcutActionDispatch>() };
 
         void _ShowAboutDialog();