diff --git a/hermes_cli/gateway_windows.py b/hermes_cli/gateway_windows.py
index 08c7d8c019c94..d28a62d5ce1df 100644
--- a/hermes_cli/gateway_windows.py
+++ b/hermes_cli/gateway_windows.py
@@ -484,6 +484,13 @@ def _install_scheduled_task(task_name: str, script_path: Path) -> tuple[bool, st
     for argv in variants:
         code, out, err = _exec_schtasks(argv)
         if code == 0:
+            limit_ok, limit_detail = _disable_scheduled_task_time_limit(task_name)
+            if not limit_ok:
+                return (
+                    False,
+                    f"Created Scheduled Task {task_name!r}, but failed to disable the default "
+                    f"72-hour time limit: {limit_detail}",
+                )
             return (True, f"Created Scheduled Task {task_name!r}")
         last_code, last_err = code, (err or out or "")
     if delete_detail and "cannot find" not in delete_detail.lower():
@@ -491,6 +498,49 @@ def _install_scheduled_task(task_name: str, script_path: Path) -> tuple[bool, st
     return (False, f"schtasks /Create failed (code {last_code}): {last_err.strip()}")
 
 
+def _disable_scheduled_task_time_limit(task_name: str) -> tuple[bool, str]:
+    """Disable Windows Task Scheduler's default 72-hour execution time limit."""
+    _assert_windows()
+    powershell = shutil.which("powershell.exe") or shutil.which("pwsh.exe")
+    if powershell is None:
+        return (False, "PowerShell not found on PATH")
+
+    script = (
+        "$ErrorActionPreference = 'Stop'; "
+        "$task = Get-ScheduledTask -TaskName $env:HERMES_TASK_NAME; "
+        "$task.Settings.ExecutionTimeLimit = 'PT0S'; "
+        "Set-ScheduledTask -InputObject $task | Out-Null"
+    )
+    env = os.environ.copy()
+    env["HERMES_TASK_NAME"] = task_name
+    try:
+        proc = subprocess.run(
+            [
+                powershell,
+                "-NoProfile",
+                "-NonInteractive",
+                "-ExecutionPolicy",
+                "Bypass",
+                "-Command",
+                script,
+            ],
+            capture_output=True,
+            text=True,
+            encoding=_schtasks_encoding(),
+            errors="replace",
+            timeout=_SCHTASKS_TIMEOUT_S,
+            creationflags=0x08000000,  # CREATE_NO_WINDOW
+            env=env,
+        )
+    except subprocess.TimeoutExpired:
+        return (False, f"PowerShell timed out after {_SCHTASKS_TIMEOUT_S}s")
+    except OSError as e:
+        return (False, f"PowerShell invocation failed: {e}")
+
+    detail = (proc.stderr or proc.stdout or "").strip()
+    if proc.returncode != 0:
+        return (False, detail or f"PowerShell exited with code {proc.returncode}")
+    return (True, "ExecutionTimeLimit set to PT0S")
 
 
 def _install_startup_entry(script_path: Path) -> Path:
diff --git a/tests/hermes_cli/test_gateway_windows.py b/tests/hermes_cli/test_gateway_windows.py
index 43f2b01dbf953..857575502f67d 100644
--- a/tests/hermes_cli/test_gateway_windows.py
+++ b/tests/hermes_cli/test_gateway_windows.py
@@ -241,6 +241,11 @@ def test_install_scheduled_task_recreates_instead_of_change(monkeypatch, tmp_pat
     script_path = tmp_path / "Hermes_Gateway_alice.cmd"
 
     monkeypatch.setattr(gateway_windows, "_assert_windows", lambda: None)
+    monkeypatch.setattr(
+        gateway_windows,
+        "_disable_scheduled_task_time_limit",
+        lambda task_name: calls.append(("disable_limit", task_name)) or (True, "ok"),
+    )
 
     def fake_schtasks(args):
         calls.append(tuple(args))
@@ -259,6 +264,59 @@ def fake_schtasks(args):
     assert calls[1][0] == "/Create"
     assert "/SC" in calls[1]
     assert "ONLOGON" in calls[1]
+    assert ("disable_limit", "Hermes_Gateway_alice") in calls
+
+
+def test_install_scheduled_task_fails_if_time_limit_cannot_be_disabled(monkeypatch, tmp_path):
+    """A gateway task with Windows' default 72h limit is not a valid install."""
+    script_path = tmp_path / "Hermes_Gateway_alice.cmd"
+
+    monkeypatch.setattr(gateway_windows, "_assert_windows", lambda: None)
+    monkeypatch.setattr(
+        gateway_windows,
+        "_exec_schtasks",
+        lambda args: (0, "SUCCESS", "") if args[0] in {"/Delete", "/Create"} else (1, "", "unexpected"),
+    )
+    monkeypatch.setattr(
+        gateway_windows,
+        "_disable_scheduled_task_time_limit",
+        lambda task_name: (False, "Set-ScheduledTask failed"),
+    )
+
+    ok, detail = gateway_windows._install_scheduled_task("Hermes_Gateway_alice", script_path)
+
+    assert ok is False
+    assert "72-hour time limit" in detail
+    assert "Set-ScheduledTask failed" in detail
+
+
+def test_disable_scheduled_task_time_limit_sets_pt0s(monkeypatch):
+    """PT0S disables the Task Scheduler execution time limit."""
+    captured: dict[str, object] = {}
+
+    class _FakeCompleted:
+        returncode = 0
+        stdout = ""
+        stderr = ""
+
+    def fake_run(cmd, **kwargs):
+        captured["cmd"] = cmd
+        captured.update(kwargs)
+        return _FakeCompleted()
+
+    monkeypatch.setattr(gateway_windows, "_assert_windows", lambda: None)
+    monkeypatch.setattr(gateway_windows.shutil, "which", lambda name: r"C:\\Windows\\System32\\WindowsPowerShell\\v1.0\\powershell.exe")
+    monkeypatch.setattr(gateway_windows.subprocess, "run", fake_run)
+
+    ok, detail = gateway_windows._disable_scheduled_task_time_limit("Hermes_Gateway_alice")
+
+    assert ok is True
+    assert "PT0S" in detail
+    command = captured["cmd"]
+    assert isinstance(command, list)
+    assert "Set-ScheduledTask" in command[-1]
+    assert "ExecutionTimeLimit = 'PT0S'" in command[-1]
+    assert captured["env"]["HERMES_TASK_NAME"] == "Hermes_Gateway_alice"
 
 
 def test_install_scheduled_task_success_start_now_uses_direct_spawn_not_task_run(monkeypatch, tmp_path, capsys):