diff --git a/Extension/src/common.ts b/Extension/src/common.ts
index f32502b91..f906154dc 100644
--- a/Extension/src/common.ts
+++ b/Extension/src/common.ts
@@ -417,21 +417,18 @@ export function getHttpsProxyAgent(): HttpsProxyAgent | undefined {
     return new HttpsProxyAgent(proxyOptions);
 }
 
-/** Creates a file if it doesn't exist */
-function touchFile(file: string): Promise<void> {
-    return new Promise<void>((resolve, reject) => {
-        fs.writeFile(file, "", (err) => {
-            if (err) {
-                reject(err);
-            }
-
-            resolve();
-        });
-    });
-}
+export interface InstallLockContents {
+    platform: string;
+    architecture: string;
+};
 
-export function touchInstallLockFile(): Promise<void> {
-    return touchFile(getInstallLockPath());
+export function touchInstallLockFile(info: PlatformInformation): Promise<void> {
+    const installLockObject: InstallLockContents = {
+        platform: info.platform,
+        architecture: info.architecture
+    };
+    const content: string = JSON.stringify(installLockObject);
+    return writeFileText(getInstallLockPath(), content);
 }
 
 export function touchExtensionFolder(): Promise<void> {
@@ -503,20 +500,6 @@ export function checkInstallLockFile(): Promise<boolean> {
     return checkFileExists(getInstallLockPath());
 }
 
-/** Get the platform that the installed binaries belong to.*/
-export function getInstalledBinaryPlatform(): string | undefined {
-    // the LLVM/bin folder is utilized to identify the platform
-    let installedPlatform: string | undefined;
-    if (checkFileExistsSync(path.join(extensionPath, "LLVM/bin/clang-format.exe"))) {
-        installedPlatform = "win32";
-    } else if (checkFileExistsSync(path.join(extensionPath, "LLVM/bin/clang-format.darwin"))) {
-        installedPlatform = "darwin";
-    } else if (checkFileExistsSync(path.join(extensionPath, "LLVM/bin/clang-format"))) {
-        installedPlatform = "linux";
-    }
-    return installedPlatform;
-}
-
 /** Check if the core binaries exists in extension's installation folder */
 export async function checkInstallBinariesExist(): Promise<boolean> {
     if (!checkInstallLockFile()) {
diff --git a/Extension/src/main.ts b/Extension/src/main.ts
index 9512f0f2c..611f98eb5 100644
--- a/Extension/src/main.ts
+++ b/Extension/src/main.ts
@@ -75,38 +75,71 @@ export async function activate(context: vscode.ExtensionContext): Promise<CppToo
 
     await processRuntimeDependencies();
 
-    const installedPlatform: string | undefined = util.getInstalledBinaryPlatform();
+    const promptForMacArchictureMismatch: PersistentState<boolean> = new PersistentState<boolean>("CPP.promptForMacArchictureMismatch", true);
+
+    // Read archictures of binaries from install.lock
+    const fileContents: string = await util.readFileText(util.getInstallLockPath());
+    let installedPlatformAndArchitecture: util.InstallLockContents;
+    // Just in case we're debugging with an existing install.lock that is empty, assume current platform if empty.
+    if (fileContents.length === 0) {
+        installedPlatformAndArchitecture = {
+            platform: process.platform,
+            architecture: arch
+        };
+    } else {
+        installedPlatformAndArchitecture = <util.InstallLockContents>JSON.parse(fileContents);
+    }
 
     // Check the main binaries files to declare if the extension has been installed successfully.
-    if (installedPlatform && process.platform !== installedPlatform) {
+    if (process.platform !== installedPlatformAndArchitecture.platform
+        || (arch !== installedPlatformAndArchitecture.architecture && (arch !== "x64" || installedPlatformAndArchitecture.architecture !== 'x86' || process.platform !== "win32"))) {
         // Check if the correct offline/insiders vsix is installed on the correct platform.
         const platformInfo: PlatformInformation = await PlatformInformation.GetPlatformInformation();
         const vsixName: string = vsixNameForPlatform(platformInfo);
-        errMsg = localize("native.binaries.not.supported", "This {0} version of the extension is incompatible with your OS. Please download and install the \"{1}\" version of the extension.", GetOSName(installedPlatform), vsixName);
-        const downloadLink: string = localize("download.button", "Go to Download Page");
-        vscode.window.showErrorMessage(errMsg, downloadLink).then(async (selection) => {
-            if (selection === downloadLink) {
-                vscode.env.openExternal(vscode.Uri.parse(releaseDownloadUrl));
-            }
-        });
-    } else if (!(await util.checkInstallBinariesExist())) {
-        errMsg = localize("extension.installation.failed", "The C/C++ extension failed to install successfully. You will need to repair or reinstall the extension for C/C++ language features to function properly.");
-        const reload: string = localize("remove.extension", "Attempt to Repair");
-        vscode.window.showErrorMessage(errMsg, reload).then(async (value?: string) => {
-            if (value === reload) {
-                await util.removeInstallLockFile();
-                vscode.commands.executeCommand("workbench.action.reloadWindow");
-            }
-        });
-    } else if (!(await util.checkInstallJsonsExist())) {
-        // Check the Json files to declare if the extension has been installed successfully.
-        errMsg = localize("jason.files.missing", "The C/C++ extension failed to install successfully. You will need to reinstall the extension for C/C++ language features to function properly.");
         const downloadLink: string = localize("download.button", "Go to Download Page");
-        vscode.window.showErrorMessage(errMsg, downloadLink).then(async (selection) => {
-            if (selection === downloadLink) {
-                vscode.env.openExternal(vscode.Uri.parse(releaseDownloadUrl));
+        if (installedPlatformAndArchitecture.platform === 'darwin' && installedPlatformAndArchitecture.architecture === "x64" && arch === "arm64") {
+            if (promptForMacArchictureMismatch.Value) {
+                // Display a message specifically referring the user to the ARM64 Mac build on ARM64 Mac.
+                errMsg = localize("native.binaries.mismatch.osx", "This Intel version of the extension has been installed.  Since you are on an Apple Silicon Mac, we recommend installing the Apple Silicon version of the extension.");
+                promptForMacArchictureMismatch.Value = false;
+                vscode.window.showErrorMessage(errMsg, downloadLink).then(async (selection) => {
+                    if (selection === downloadLink) {
+                        vscode.env.openExternal(vscode.Uri.parse(releaseDownloadUrl));
+                    }
+                });
             }
-        });
+        } else {
+            // Reset the persistent boolean tracking whether to warn the user of architecture mismatch on OSX.
+            promptForMacArchictureMismatch.Value = true;
+            errMsg = localize("native.binaries.not.supported", "This {0} version of the extension is incompatible with your OS. Please download and install the \"{1}\" version of the extension.", GetOSName(installedPlatformAndArchitecture.platform), vsixName);
+            vscode.window.showErrorMessage(errMsg, downloadLink).then(async (selection) => {
+                if (selection === downloadLink) {
+                    vscode.env.openExternal(vscode.Uri.parse(releaseDownloadUrl));
+                }
+            });
+        }
+    } else {
+        // Reset the persistent boolean tracking whether to warn the user of architecture mismatch on OSX.
+        promptForMacArchictureMismatch.Value = true;
+        if (!(await util.checkInstallBinariesExist())) {
+            errMsg = localize("extension.installation.failed", "The C/C++ extension failed to install successfully. You will need to repair or reinstall the extension for C/C++ language features to function properly.");
+            const reload: string = localize("remove.extension", "Attempt to Repair");
+            vscode.window.showErrorMessage(errMsg, reload).then(async (value?: string) => {
+                if (value === reload) {
+                    await util.removeInstallLockFile();
+                    vscode.commands.executeCommand("workbench.action.reloadWindow");
+                }
+            });
+        } else if (!(await util.checkInstallJsonsExist())) {
+            // Check the Json files to declare if the extension has been installed successfully.
+            errMsg = localize("jason.files.missing", "The C/C++ extension failed to install successfully. You will need to reinstall the extension for C/C++ language features to function properly.");
+            const downloadLink: string = localize("download.button", "Go to Download Page");
+            vscode.window.showErrorMessage(errMsg, downloadLink).then(async (selection) => {
+                if (selection === downloadLink) {
+                    vscode.env.openExternal(vscode.Uri.parse(releaseDownloadUrl));
+                }
+            });
+        }
     }
 
     return cppTools;
@@ -219,7 +252,7 @@ async function onlineInstallation(info: PlatformInformation): Promise<void> {
     await rewriteManifest();
 
     setInstallationStage('touchInstallLockFile');
-    await touchInstallLockFile();
+    await touchInstallLockFile(info);
 
     setInstallationStage('postInstall');
     await postInstall(info);
@@ -311,8 +344,8 @@ function removeUnnecessaryFile(): Promise<void> {
     return Promise.resolve();
 }
 
-function touchInstallLockFile(): Promise<void> {
-    return util.touchInstallLockFile();
+function touchInstallLockFile(info: PlatformInformation): Promise<void> {
+    return util.touchInstallLockFile(info);
 }
 
 function handleError(error: any): void {