diff --git a/apps/desktop/src/main.ts b/apps/desktop/src/main.ts
index f88743dc4bbf05e9c939fd7cb5e24eb052afdd7c..54a521f9f0253ac2d829b4552047b89fb46640f6 100644
--- a/apps/desktop/src/main.ts
+++ b/apps/desktop/src/main.ts
@@ -15,6 +15,7 @@ import { NetService } from "@t3tools/shared/Net";
 import { RotatingFileSink } from "@t3tools/shared/logging";
 import { showDesktopConfirmDialog } from "./confirmDialog";
 import { fixPath } from "./fixPath";
+import { getAutoUpdateDisabledReason, shouldBroadcastDownloadProgress } from "./updateState";
 
 fixPath();
 
@@ -425,11 +426,28 @@ function dispatchMenuAction(action: string): void {
 }
 
 function handleCheckForUpdatesMenuClick(): void {
-  if (!shouldEnableAutoUpdates()) {
+  const disabledReason = getAutoUpdateDisabledReason({
+    isDevelopment,
+    isPackaged: app.isPackaged,
+    platform: process.platform,
+    appImage: process.env.APPIMAGE,
+    disabledByEnv: process.env.T3CODE_DISABLE_AUTO_UPDATE === "1",
+  });
+  if (disabledReason) {
     console.info("[desktop-updater] Manual update check requested, but updates are disabled.");
+    void dialog.showMessageBox({
+      type: "info",
+      title: "Updates unavailable",
+      message: "Automatic updates are not available right now.",
+      detail: disabledReason,
+      buttons: ["OK"],
+    });
     return;
   }
 
+  if (!BrowserWindow.getAllWindows().length) {
+    mainWindow = createWindow();
+  }
   void checkForUpdates("menu");
 }
 
@@ -562,17 +580,15 @@ function setUpdateState(patch: Partial<DesktopUpdateState>): void {
 }
 
 function shouldEnableAutoUpdates(): boolean {
-  if (isDevelopment || !app.isPackaged) {
-    return false;
-  }
-  if (process.env.T3CODE_DISABLE_AUTO_UPDATE === "1") {
-    return false;
-  }
-  if (process.platform === "linux" && !process.env.APPIMAGE) {
-    // electron-updater only supports Linux auto-updates when running from AppImage.
-    return false;
-  }
-  return true;
+  return (
+    getAutoUpdateDisabledReason({
+      isDevelopment,
+      isPackaged: app.isPackaged,
+      platform: process.platform,
+      appImage: process.env.APPIMAGE,
+      disabledByEnv: process.env.T3CODE_DISABLE_AUTO_UPDATE === "1",
+    }) === null
+  );
 }
 
 async function checkForUpdates(reason: string): Promise<void> {
@@ -719,11 +735,16 @@ function configureAutoUpdater(): void {
   });
   autoUpdater.on("download-progress", (progress) => {
     const percent = Math.floor(progress.percent);
-    setUpdateState({
-      status: "downloading",
-      downloadPercent: progress.percent,
-      message: null,
-    });
+    if (
+      shouldBroadcastDownloadProgress(updateState, progress.percent) ||
+      updateState.message !== null
+    ) {
+      setUpdateState({
+        status: "downloading",
+        downloadPercent: progress.percent,
+        message: null,
+      });
+    }
     const milestone = percent - (percent % 10);
     if (milestone > lastLoggedDownloadMilestone) {
       lastLoggedDownloadMilestone = milestone;
diff --git a/apps/desktop/src/updateState.test.ts b/apps/desktop/src/updateState.test.ts
new file mode 100644
index 0000000000000000000000000000000000000000..8b3fa7cb82ed21b5bacc8f0579601ab2cf329b91
--- /dev/null
+++ b/apps/desktop/src/updateState.test.ts
@@ -0,0 +1,82 @@
+import { describe, expect, it } from "vitest";
+import type { DesktopUpdateState } from "@t3tools/contracts";
+
+import { getAutoUpdateDisabledReason, shouldBroadcastDownloadProgress } from "./updateState";
+
+const baseState: DesktopUpdateState = {
+  enabled: true,
+  status: "idle",
+  currentVersion: "1.0.0",
+  availableVersion: null,
+  downloadedVersion: null,
+  downloadPercent: null,
+  checkedAt: null,
+  message: null,
+};
+
+describe("shouldBroadcastDownloadProgress", () => {
+  it("broadcasts the first downloading progress update", () => {
+    expect(
+      shouldBroadcastDownloadProgress(
+        { ...baseState, status: "downloading", downloadPercent: null },
+        1,
+      ),
+    ).toBe(true);
+  });
+
+  it("skips progress updates within the same 10% bucket", () => {
+    expect(
+      shouldBroadcastDownloadProgress(
+        { ...baseState, status: "downloading", downloadPercent: 11.2 },
+        18.7,
+      ),
+    ).toBe(false);
+  });
+
+  it("broadcasts progress updates when a new 10% bucket is reached", () => {
+    expect(
+      shouldBroadcastDownloadProgress(
+        { ...baseState, status: "downloading", downloadPercent: 19.9 },
+        20.1,
+      ),
+    ).toBe(true);
+  });
+});
+
+describe("getAutoUpdateDisabledReason", () => {
+  it("reports development builds as disabled", () => {
+    expect(
+      getAutoUpdateDisabledReason({
+        isDevelopment: true,
+        isPackaged: false,
+        platform: "darwin",
+        appImage: undefined,
+        disabledByEnv: false,
+      }),
+    ).toContain("packaged production builds");
+  });
+
+  it("reports env-disabled auto updates", () => {
+    expect(
+      getAutoUpdateDisabledReason({
+        isDevelopment: false,
+        isPackaged: true,
+        platform: "darwin",
+        appImage: undefined,
+        disabledByEnv: true,
+      }),
+    ).toContain("T3CODE_DISABLE_AUTO_UPDATE");
+  });
+
+  it("reports linux non-AppImage builds as disabled", () => {
+    expect(
+      getAutoUpdateDisabledReason({
+        isDevelopment: false,
+        isPackaged: true,
+        platform: "linux",
+        appImage: undefined,
+        disabledByEnv: false,
+      }),
+    ).toContain("AppImage");
+  });
+});
diff --git a/apps/desktop/src/updateState.ts b/apps/desktop/src/updateState.ts
new file mode 100644
index 0000000000000000000000000000000000000000..b6291d2e5bbb62b2aed79db8831bea2a9b6788c5
--- /dev/null
+++ b/apps/desktop/src/updateState.ts
@@ -0,0 +1,38 @@
+import type { DesktopUpdateState } from "@t3tools/contracts";
+
+export function shouldBroadcastDownloadProgress(
+  currentState: DesktopUpdateState,
+  nextPercent: number,
+): boolean {
+  if (currentState.status !== "downloading") {
+    return true;
+  }
+
+  const currentPercent = currentState.downloadPercent;
+  if (currentPercent === null) {
+    return true;
+  }
+
+  const previousStep = Math.floor(currentPercent / 10);
+  const nextStep = Math.floor(nextPercent / 10);
+  return nextStep > previousStep || nextPercent === 100;
+}
+
+export function getAutoUpdateDisabledReason(args: {
+  isDevelopment: boolean;
+  isPackaged: boolean;
+  platform: NodeJS.Platform;
+  appImage?: string | undefined;
+  disabledByEnv: boolean;
+}): string | null {
+  if (args.isDevelopment || !args.isPackaged) {
+    return "Automatic updates are only available in packaged production builds.";
+  }
+  if (args.disabledByEnv) {
+    return "Automatic updates are disabled by the T3CODE_DISABLE_AUTO_UPDATE setting.";
+  }
+  if (args.platform === "linux" && !args.appImage) {
+    return "Automatic updates on Linux require running the AppImage build.";
+  }
+  return null;
+}