diff --git a/src/plaud_tools/tray/process_launch.py b/src/plaud_tools/tray/process_launch.py
index cc7d228..6a7ff4b 100644
--- a/src/plaud_tools/tray/process_launch.py
+++ b/src/plaud_tools/tray/process_launch.py
@@ -43,6 +43,14 @@
 # future Python drops the attribute.
 _CREATE_BREAKAWAY_FROM_JOB: int = getattr(subprocess, "CREATE_BREAKAWAY_FROM_JOB", 0x01000000)
 
+# On a stock machine the default PowerShell execution policy (``Restricted``)
+# refuses to run any script, and an interactive prompt would hang forever with
+# stdio wired to DEVNULL. Every launch needs both flags to run reliably from
+# the no-console frozen tray; only the updater passed them explicitly, so the
+# uninstall-helper and toast launches could still fail on a stock policy
+# (#142). Injected here (once) so every call site gets them for free.
+_REQUIRED_FLAGS: tuple[str, ...] = ("-NonInteractive", "-ExecutionPolicy", "Bypass")
+
 
 def launch_hidden_powershell(
     args: list[str],
@@ -61,7 +69,15 @@ def launch_hidden_powershell(
     this): ``CREATE_BREAKAWAY_FROM_JOB`` is requested, with a same-args retry
     (flag dropped) if the enclosing Job Object forbids it -- so the operation
     is never worse off than launching without the flag at all.
+
+    ``-NonInteractive -ExecutionPolicy Bypass`` are injected right after
+    ``args[0]`` (the powershell.exe path) unless already present, so every
+    caller is immune to a stock ``Restricted`` execution policy without
+    having to remember the flags itself (#142).
     """
+    if "-NonInteractive" not in args:
+        args = [args[0], *_REQUIRED_FLAGS, *args[1:]]
+
     base_flags = subprocess.CREATE_NO_WINDOW | subprocess.CREATE_NEW_PROCESS_GROUP
     kwargs: dict[str, object] = {
         "stdin": subprocess.DEVNULL,
diff --git a/src/plaud_tools/tray/updater.py b/src/plaud_tools/tray/updater.py
index 1c6de8c..ae633aa 100644
--- a/src/plaud_tools/tray/updater.py
+++ b/src/plaud_tools/tray/updater.py
@@ -53,13 +53,12 @@ def _launch_updater(ps_path: Path) -> subprocess.Popen[bytes]:
     and update.ps1 then waits for the tray to exit before replacing its files.
     Delegates to :func:`process_launch.launch_hidden_powershell` (#142) for the
     safe-stdio + job-breakaway launch semantics shared with the uninstaller.
+    ``-NonInteractive -ExecutionPolicy Bypass`` are injected by the shared
+    helper itself, so they aren't repeated here.
     """
     args = [
         _POWERSHELL_EXE,
         "-NoProfile",
-        "-NonInteractive",
-        "-ExecutionPolicy",
-        "Bypass",
         "-WindowStyle",
         "Hidden",
         "-File",
diff --git a/tests/test_process_launch.py b/tests/test_process_launch.py
index 93953fe..60a6191 100644
--- a/tests/test_process_launch.py
+++ b/tests/test_process_launch.py
@@ -144,6 +144,52 @@ def fake_popen(args, creationflags=0, **kwargs):
     assert len(calls) == 1
 
 
+def test_execution_policy_flags_injected_when_missing(monkeypatch):
+    """A stock machine's default ``Restricted`` execution policy refuses to run
+    any script; every call site must get ``-NonInteractive -ExecutionPolicy
+    Bypass`` even if it forgot to pass them itself (#142).
+    """
+    seen: dict[str, list[str]] = {}
+
+    def fake_popen(args, **kwargs):
+        seen["args"] = args
+        return _FakeProc()
+
+    monkeypatch.setattr(process_launch.subprocess, "Popen", fake_popen)
+
+    launch_hidden_powershell(["powershell.exe", "-WindowStyle", "Hidden", "-Command", "Write-Host hi"])
+
+    assert seen["args"] == [
+        "powershell.exe",
+        "-NonInteractive",
+        "-ExecutionPolicy",
+        "Bypass",
+        "-WindowStyle",
+        "Hidden",
+        "-Command",
+        "Write-Host hi",
+    ]
+
+
+def test_execution_policy_flags_not_duplicated(monkeypatch):
+    """A caller that already passes the flags (the updater, historically)
+    must not get them injected a second time.
+    """
+    seen: dict[str, list[str]] = {}
+
+    def fake_popen(args, **kwargs):
+        seen["args"] = args
+        return _FakeProc()
+
+    monkeypatch.setattr(process_launch.subprocess, "Popen", fake_popen)
+
+    original = ["powershell.exe", "-NonInteractive", "-ExecutionPolicy", "Bypass", "-File", "x.ps1"]
+    launch_hidden_powershell(original)
+
+    assert seen["args"] == original
+    assert seen["args"].count("-NonInteractive") == 1
+
+
 def test_cwd_is_forwarded(monkeypatch):
     seen: dict[str, object] = {}