diff --git a/scripts/e2e/telegram-user-credential-io.ts b/scripts/e2e/telegram-user-credential-io.ts
index 0201d1804eb7..7d142e6a0720 100644
--- a/scripts/e2e/telegram-user-credential-io.ts
+++ b/scripts/e2e/telegram-user-credential-io.ts
@@ -273,9 +273,15 @@ export function signalChildProcessTree(
       args.push("/F");
     }
     const result = runTaskkill("taskkill", args, { stdio: "ignore" });
-    if (!result.error && result.status === 0) {
+    if (!result?.error && result?.status === 0) {
       return;
     }
+    if (signal !== "SIGKILL") {
+      const forceResult = runTaskkill("taskkill", [...args, "/F"], { stdio: "ignore" });
+      if (!forceResult?.error && forceResult?.status === 0) {
+        return;
+      }
+    }
   }
   child.kill(signal);
 }
diff --git a/test/scripts/telegram-user-credential.test.ts b/test/scripts/telegram-user-credential.test.ts
index 1f1974add58c..a0c44006250c 100644
--- a/test/scripts/telegram-user-credential.test.ts
+++ b/test/scripts/telegram-user-credential.test.ts
@@ -432,6 +432,30 @@ setInterval(() => {}, 1000);
     expect(child.kill).not.toHaveBeenCalled();
   });
 
+  it("force-kills Windows credential helper process trees when graceful taskkill fails", () => {
+    const child = {
+      kill: vi.fn(),
+      pid: 12345,
+    };
+    const runTaskkill = vi
+      .fn()
+      .mockReturnValueOnce({ error: undefined, status: 1 })
+      .mockReturnValueOnce({ error: undefined, status: 0 });
+
+    signalChildProcessTree(child, "SIGTERM", {
+      platform: "win32",
+      runTaskkill,
+    });
+
+    expect(runTaskkill).toHaveBeenNthCalledWith(1, "taskkill", ["/PID", "12345", "/T"], {
+      stdio: "ignore",
+    });
+    expect(runTaskkill).toHaveBeenNthCalledWith(2, "taskkill", ["/PID", "12345", "/T", "/F"], {
+      stdio: "ignore",
+    });
+    expect(child.kill).not.toHaveBeenCalled();
+  });
+
   it.runIf(process.platform !== "win32")(
     "exits promptly after forwarded SIGTERM children exit cleanly",
     async () => {