diff --git a/CHANGELOG.md b/CHANGELOG.md
index a7721797709..64baf0be4c8 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -49,6 +49,7 @@ Docs: https://docs.openclaw.ai
 - Control UI: render Dream Diary prose through the sanitized markdown pipeline, so diary bold/italic/header markdown no longer appears as literal source text. Fixes #62413.
 - Control UI: render tool results whose output arrives as text-block arrays and give expanded tool output a scrollable block, so read/exec output remains visible in WebChat. Fixes #77054.
 - MCP: include serialized conversation/message payloads in the primary text content for `conversations_list` and `messages_read`, while preserving `structuredContent` for capable clients. Fixes #77024.
+- Media: treat `EPERM` from the post-write media fsync step as best-effort, allowing WebChat and channel uploads to finish on Windows filesystems that reject `fsync` after a successful write. Fixes #76844.
 - Diagnostics: keep webhook/message OTEL attributes and Prometheus delivery labels low-cardinality and omit raw chat/message IDs from spans, so progress-draft and message-tool modes do not leak high-cardinality messaging identifiers.
 - Google Meet: stop advertising legacy `mode: "realtime"` to agents and config UIs, while keeping it as a hidden compatibility alias for `mode: "agent"`, so new joins use the STT -> OpenClaw agent -> TTS path instead of selecting the direct realtime voice fallback.
 - Google Meet: add `chrome.audioBufferBytes` for generated command-pair SoX audio commands and lower the default buffer from SoX's 8192 bytes to 4096 bytes to reduce Chrome talk-back latency.
diff --git a/src/media/store.test.ts b/src/media/store.test.ts
index bb536f00a88..44f84d01ebf 100644
--- a/src/media/store.test.ts
+++ b/src/media/store.test.ts
@@ -341,6 +341,35 @@ describe("media store", () => {
         });
       },
     },
+    {
+      name: "saves buffers when the best-effort fsync step reports EPERM",
+      run: async () => {
+        await withTempStore(async (store) => {
+          const originalOpen = fs.open.bind(fs);
+          vi.spyOn(fs, "open").mockImplementation(async (...args) => {
+            const handle = await originalOpen(...args);
+            const filePath = args[0];
+            if (
+              typeof filePath === "string" &&
+              filePath.includes(`${path.sep}fsync-eperm${path.sep}`)
+            ) {
+              vi.spyOn(handle, "sync").mockRejectedValueOnce(
+                Object.assign(new Error("operation not permitted"), { code: "EPERM" }),
+              );
+            }
+            return handle;
+          });
+
+          const saved = await store.saveMediaBuffer(
+            Buffer.from("docx"),
+            "application/zip",
+            "fsync-eperm",
+          );
+
+          await expect(fs.readFile(saved.path, "utf8")).resolves.toBe("docx");
+        });
+      },
+    },
     {
       name: "rejects traversal media subdirs before saving buffers",
       run: async () => {
diff --git a/src/media/store.ts b/src/media/store.ts
index 0e1055fbb18..e1086921349 100644
--- a/src/media/store.ts
+++ b/src/media/store.ts
@@ -351,7 +351,7 @@ async function writeSavedMediaBuffer(params: {
       await fs.writeFile(tempDest, params.buffer, { mode: MEDIA_FILE_MODE });
       const handle = await fs.open(tempDest, "r");
       try {
-        await handle.sync();
+        await syncSavedMediaHandle(handle);
       } finally {
         await handle.close();
       }
@@ -364,6 +364,17 @@ async function writeSavedMediaBuffer(params: {
   return dest;
 }
 
+async function syncSavedMediaHandle(handle: fs.FileHandle): Promise<void> {
+  try {
+    await handle.sync();
+  } catch (err) {
+    if ((err as NodeJS.ErrnoException | undefined)?.code === "EPERM") {
+      return;
+    }
+    throw err;
+  }
+}
+
 export type SaveMediaSourceErrorCode =
   | "invalid-path"
   | "not-found"