diff --git a/scripts/verify-windows-installer-lifecycle.mjs b/scripts/verify-windows-installer-lifecycle.mjs
index 4f20445308..4e14c3c2f2 100644
--- a/scripts/verify-windows-installer-lifecycle.mjs
+++ b/scripts/verify-windows-installer-lifecycle.mjs
@@ -21,7 +21,10 @@ function delay(milliseconds) {
   return new Promise((resolvePromise) => setTimeout(resolvePromise, milliseconds));
 }
 
-export async function listInstalledProcesses(installDirectory, { run = runCommand } = {}) {
+export async function listInstalledProcesses(
+  installDirectory,
+  { run = runCommand, timeoutMs = 10_000 } = {},
+) {
   const root = `${resolve(installDirectory)}${sep}`;
   const script = String.raw`
 $root = [IO.Path]::GetFullPath(${powerShellLiteral(root)})
@@ -37,7 +40,21 @@ $matches = @(
 )
 $matches | ConvertTo-Json -Compress
 `;
-  const { stdout } = await run('powershell', ['-NoProfile', '-NonInteractive', '-Command', script]);
+  // Bounded because this probe runs inside deadline-bounded poll loops, and a
+  // loop only checks its deadline between probes: an unbounded one makes the
+  // deadline a lie. A `Get-CimInstance Win32_Process` query hung for the rest
+  // of the job during an auto-update relaunch, so the 120s relaunch deadline
+  // never fired and the runner cancelled the run an hour later.
+  //
+  // Well under the 60s and 120s budgets above it, so a stalled probe leaves
+  // room for several more attempts rather than consuming the whole window: a
+  // loop that can only try twice cannot survive a stall, which is the entire
+  // point of tolerating one.
+  const { stdout } = await run(
+    'powershell',
+    ['-NoProfile', '-NonInteractive', '-Command', script],
+    { timeoutMs },
+  );
   if (!stdout.trim()) return [];
   const parsed = JSON.parse(stdout);
   return Array.isArray(parsed) ? parsed : [parsed];
@@ -53,16 +70,38 @@ export async function waitForInstalledProcessesToExit(
   } = {},
 ) {
   const deadline = Date.now() + timeoutMs;
-  let processes = await listProcesses(installDirectory);
-  while (processes.length > 0) {
+  let processes = [];
+  let observed = false;
+  let probeError;
+  for (;;) {
+    try {
+      processes = await listProcesses(installDirectory);
+      observed = true;
+      probeError = undefined;
+      if (processes.length === 0) return;
+    } catch (error) {
+      // A bounded probe that fails says nothing about the processes, so the
+      // loop's own deadline stays the authority — the Windows process query
+      // stalls while an installer is churning the process table, and one
+      // stalled probe must not decide a verification.
+      probeError = error;
+    }
     if (Date.now() >= deadline) {
+      // Never having seen the process table is a different fault from seeing
+      // processes that would not exit, and only one of them is about Maka.
+      if (!observed) {
+        throw new Error(
+          `Could not read the process table within ${timeoutMs}ms, so whether installed Maka processes exited is unknown.\nLast process probe failed: ${probeError?.message}`,
+        );
+      }
       const summary = processes.map(({ processId, name }) => `${name} (${processId})`).join(', ');
       throw new Error(
-        `Installed Maka processes did not exit within ${timeoutMs}ms: ${summary || '<unknown>'}.`,
+        `Installed Maka processes did not exit within ${timeoutMs}ms: ${summary || '<unknown>'}.${
+          probeError ? `\nThe last probe also failed: ${probeError.message}` : ''
+        }`,
       );
     }
     await sleep(pollIntervalMs);
-    processes = await listProcesses(installDirectory);
   }
 }