diff --git a/.changeset/gentle-bags-thank.md b/.changeset/gentle-bags-thank.md
new file mode 100644
index 0000000000..757b6ca24e
--- /dev/null
+++ b/.changeset/gentle-bags-thank.md
@@ -0,0 +1,5 @@
+---
+"app-builder-lib": patch
+---
+
+feat(appx): Update identityName for windows 10
diff --git a/packages/app-builder-lib/src/targets/AppxTarget.ts b/packages/app-builder-lib/src/targets/AppxTarget.ts
index 5a55a48864..7871d69d78 100644
--- a/packages/app-builder-lib/src/targets/AppxTarget.ts
+++ b/packages/app-builder-lib/src/targets/AppxTarget.ts
@@ -20,6 +20,31 @@ const vendorAssetsForDefaultAssets: { [key: string]: string } = {
   "Wide310x150Logo.png": "SampleAppx.310x150.png",
 }
 
+const restrictedApplicationIdValues = [
+  "CON",
+  "PRN",
+  "AUX",
+  "NUL",
+  "COM1",
+  "COM2",
+  "COM3",
+  "COM4",
+  "COM5",
+  "COM6",
+  "COM7",
+  "COM8",
+  "COM9",
+  "LPT1",
+  "LPT2",
+  "LPT3",
+  "LPT4",
+  "LPT5",
+  "LPT6",
+  "LPT7",
+  "LPT8",
+  "LPT9",
+]
+
 const DEFAULT_RESOURCE_LANG = "en-US"
 
 export default class AppXTarget extends Target {
@@ -200,13 +225,21 @@ export default class AppXTarget extends Target {
 
         case "applicationId": {
           const result = options.applicationId || options.identityName || appInfo.name
-          if (!isNaN(parseInt(result[0], 10))) {
-            let message = `AppX Application.Id can’t start with numbers: "${result}"`
-            if (options.applicationId == null) {
-              message += `\nPlease set appx.applicationId (or correct appx.identityName or name)`
-            }
+          const validCharactersRegex = /^[a-zA-Z0-9.-]+$/
+          if (result.length < 3 || result.length > 50) {
+            const message = `Appx Application.Id with a value between 3 and 50 characters in length`
+            throw new InvalidConfigurationError(message)
+          } else if (!validCharactersRegex.test(result)) {
+            const message = `AppX Application.Id cat be consists of alpha-numeric, period, and dash characters"`
+            throw new InvalidConfigurationError(message)
+          } else if (restrictedApplicationIdValues.includes(result.toUpperCase())) {
+            const message = `AppX Application.Id cannot be some values`
+            throw new InvalidConfigurationError(message)
+          } else if (options.applicationId == null) {
+            const message = `Please set appx.applicationId (or correct appx.identityName or name)`
             throw new InvalidConfigurationError(message)
           }
+
           return result
         }