diff --git a/src/main/agent-hooks/windows-hook-payload-delivery.test.ts b/src/main/agent-hooks/windows-hook-payload-delivery.test.ts
index 79d9f4f60ae..ea71fd13eaf 100644
--- a/src/main/agent-hooks/windows-hook-payload-delivery.test.ts
+++ b/src/main/agent-hooks/windows-hook-payload-delivery.test.ts
@@ -5,9 +5,9 @@
 // through it, because none of them ever piped a payload. This suite pipes one and follows
 // it to the listener, so a launcher that takes stdin away from the hook fails here (#14818).
 import { afterEach, describe, expect, it, vi } from 'vitest'
-import { spawn } from 'node:child_process'
+import { runProcess } from '../../shared/child-process/run-process'
 import { createServer, type Server } from 'node:http'
-import { mkdtempSync, readFileSync, writeFileSync } from 'node:fs'
+import { mkdtempSync, writeFileSync } from 'node:fs'
 import { removeTreeSync } from '../../shared/windows-transient-lock-removal'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
@@ -32,7 +32,9 @@ vi.mock('os', async (importOriginal) => {
 })
 
 import { ClaudeHookService } from '../claude/hook-service'
-import { WINDOWS_CMD_SAFE_PATH } from './installer-utils'
+import { MuseHookService } from '../muse/hook-service'
+import { getMuseManagedHooksPath } from '../muse/hook-settings'
+import { readHooksJson, WINDOWS_CMD_SAFE_PATH } from './installer-utils'
 import { getConfigPath, getWindowsManagedLifecycleHook } from '../claude/hook-settings'
 import { findGitBash } from './windows-git-bash-path.test-fixture'
 
@@ -89,38 +91,9 @@ function runHookCommand(
   args: string[],
   env: NodeJS.ProcessEnv
 ): Promise<HookRun> {
-  return new Promise((resolve, reject) => {
-    const child = spawn(executable, args, {
-      stdio: ['pipe', 'pipe', 'pipe'],
-      windowsHide: true,
-      env
-    })
-    let stdout = ''
-    let stderr = ''
-    let timedOut = false
-    // Why: Claude Code abandons a hook at 10s, so a launcher that strands the payload reads
-    // as a timeout to the user; fail the same way instead of hanging the suite.
-    const timer = setTimeout(() => {
-      timedOut = true
-      child.kill('SIGKILL')
-    }, 15_000)
-    child.on('error', (error) => {
-      clearTimeout(timer)
-      reject(error)
-    })
-    child.stdout.on('data', (chunk: Buffer) => {
-      stdout += chunk.toString()
-    })
-    child.stderr.on('data', (chunk: Buffer) => {
-      stderr += chunk.toString()
-    })
-    child.on('close', (exitCode) => {
-      clearTimeout(timer)
-      // Why: curl exits once the POST is written; give the listener a beat to finish reading it.
-      setTimeout(() => resolve({ exitCode, stdout, stderr, timedOut }), 250)
-    })
-    child.stdin.end(Buffer.from(PAYLOAD, 'utf8'))
-  })
+  return runProcess({ program: executable, args, env, input: PAYLOAD, timeoutMs: 15_000 }).then(
+    (result) => ({ ...result, exitCode: result.code })
+  )
 }
 
 // Why: a developer box may set HKCU\...\Command Processor\AutoRun, which cmd.exe runs before
@@ -136,7 +109,7 @@ function hookEnvironment(extra: NodeJS.ProcessEnv): NodeJS.ProcessEnv {
   const base = Object.fromEntries(
     Object.entries(process.env).filter(([key]) => !key.startsWith('ORCA_'))
   )
-  return { ...base, ...extra }
+  return { ...base, ORCA_BACKGROUND_LAUNCH: '1', ...extra }
 }
 
 describe('Windows managed hook launcher', () => {
@@ -156,6 +129,7 @@ describe.skipIf(process.platform !== 'win32')('Windows managed hook payload deli
   let server: Server | null = null
 
   afterEach(() => {
+    vi.unstubAllEnvs()
     server?.close()
     server = null
     homedirMock.mockImplementation(() => process.env.HOME ?? tmpdir())
@@ -165,58 +139,88 @@ describe.skipIf(process.platform !== 'win32')('Windows managed hook payload deli
     }
   })
 
-  it('delivers the piped payload to the hook listener through cmd.exe and Git Bash', async () => {
-    home = mkdtempSync(join(tmpdir(), 'orca-hook-payload-'))
-    homedirMock.mockReturnValue(home)
-    seedCmdAutoRunTarget(home)
-    expect(new ClaudeHookService().install().state).toBe('installed')
-
-    const settings = JSON.parse(readFileSync(getConfigPath(), 'utf8')) as {
-      hooks: Record<string, { hooks: { command: string }[] }[]>
-    }
-    // Why: assert nothing about the launcher's shape here — this test's whole value is
-    // that it fails for any launcher that loses the payload, named conhost or not.
-    const registeredCommand = settings.hooks.PreToolUse[0].hooks[0].command
-    // ...with one exception: a cmd-safe profile must reach the script with no interpreter in
-    // front of it, or #18875's per-event PowerShell start-up has quietly come back.
-    if (WINDOWS_CMD_SAFE_PATH.test(join(home, '.orca', 'agent-hooks', 'claude-hook.cmd'))) {
-      expect(registeredCommand).not.toMatch(/powershell|-EncodedCommand/i)
+  it.each([
+    {
+      name: 'Claude',
+      install: () => new ClaudeHookService().install(),
+      configPath: getConfigPath,
+      script: 'claude-hook.cmd',
+      stdout: '{}'
+    },
+    {
+      name: 'Muse',
+      install: () => new MuseHookService().install(),
+      configPath: getMuseManagedHooksPath,
+      script: 'muse-hook.cmd',
+      stdout: ''
     }
+  ])(
+    '$name delivers the piped payload through cmd.exe and Git Bash',
+    async (provider) => {
+      home = mkdtempSync(join(tmpdir(), 'orca-hook-payload-'))
+      vi.stubEnv('XDG_CONFIG_HOME', undefined)
+      homedirMock.mockReturnValue(home)
+      seedCmdAutoRunTarget(home)
+      expect(provider.install().state).toBe('installed')
 
-    const listener = await startHookListener()
-    server = listener.server
-    const env = hookEnvironment({
-      USERPROFILE: home,
-      HOME: home,
-      ORCA_AGENT_HOOK_PORT: String(listener.port),
-      ORCA_AGENT_HOOK_TOKEN: HOOK_TOKEN,
-      ORCA_PANE_KEY: PANE_KEY
-    })
+      const settings = readHooksJson(provider.configPath())
+      // Why: assert nothing about the launcher's shape here — this test's whole value is
+      // that it fails for any launcher that loses the payload, named conhost or not.
+      const registeredCommand = settings?.hooks?.PreToolUse[0]?.hooks?.[0]?.command
+      if (!registeredCommand) {
+        throw new Error('Missing managed PreToolUse command')
+      }
+      // ...with one exception: a cmd-safe profile must reach the script with no interpreter in
+      // front of it, or #18875's per-event PowerShell start-up has quietly come back.
+      if (WINDOWS_CMD_SAFE_PATH.test(join(home, '.orca', 'agent-hooks', provider.script))) {
+        expect(registeredCommand).not.toMatch(/powershell|-EncodedCommand/i)
+      }
 
-    const shells = [
-      { name: 'cmd.exe', executable: 'cmd.exe', args: ['/d', '/c', registeredCommand] },
-      { name: 'Git Bash', executable: findGitBash(), args: ['-c', registeredCommand] }
-    ]
-    for (const shell of shells) {
-      const before = listener.posts.length
-      const result = await runHookCommand(shell.executable, shell.args, env)
-      expect(result.timedOut, `${shell.name} timed out`).toBe(false)
-      expect(result.exitCode, `${shell.name} exit code`).toBe(0)
+      const listener = await startHookListener()
+      server = listener.server
+      const env = hookEnvironment({
+        USERPROFILE: home,
+        HOME: home,
+        ORCA_AGENT_HOOK_PORT: String(listener.port),
+        ORCA_AGENT_HOOK_TOKEN: HOOK_TOKEN,
+        ORCA_PANE_KEY: PANE_KEY
+      })
 
-      // Why: assert delivery before stdout so a launcher that swallows the payload fails
-      // on the symptom users report, not on some downstream difference in what it printed.
-      const posts = listener.posts.slice(before)
-      expect(posts, `${shell.name} posted exactly one hook`).toHaveLength(1)
-      // Why: byte-exact, not "non-empty" — a pseudoconsole host delivers nothing, and a
-      // code-page-translating launcher delivers a corrupted body that still looks posted.
-      expect(posts[0].payload, `${shell.name} payload`).toBe(PAYLOAD)
-      expect(posts[0].paneKey, `${shell.name} paneKey`).toBe(PANE_KEY)
-      expect(posts[0].token, `${shell.name} token`).toBe(HOOK_TOKEN)
+      const shells = [
+        { name: 'cmd.exe', executable: 'cmd.exe', args: ['/d', '/c', registeredCommand] },
+        { name: 'Git Bash', executable: findGitBash(), args: ['-c', registeredCommand] }
+      ]
+      for (const shell of shells) {
+        const before = listener.posts.length
+        const result = await runHookCommand(shell.executable, shell.args, env)
+        expect(result.timedOut, `${shell.name} timed out`).toBe(false)
+        expect(result.exitCode, `${shell.name} exit code`).toBe(0)
 
-      expect(result.stderr, `${shell.name} stderr`).toBe('')
-      // Why: compat consumers gate the tool call on parseable stdout (#14818).
-      expect(result.stdout.trim(), `${shell.name} stdout`).toBe('{}')
-    }
-    // Why: two shell launches plus a real install can overrun the default under load.
-  }, 60_000)
+        // Why: assert delivery before stdout so a launcher that swallows the payload fails
+        // on the symptom users report, not on some downstream difference in what it printed.
+        const posts = listener.posts.slice(before)
+        expect(posts, `${shell.name} posted exactly one hook`).toHaveLength(1)
+        // Why: byte-exact, not "non-empty" — a pseudoconsole host delivers nothing, and a
+        // code-page-translating launcher delivers a corrupted body that still looks posted.
+        expect(posts[0].payload, `${shell.name} payload`).toBe(PAYLOAD)
+        expect(posts[0].paneKey, `${shell.name} paneKey`).toBe(PANE_KEY)
+        expect(posts[0].token, `${shell.name} token`).toBe(HOOK_TOKEN)
+
+        expect(result.stderr, `${shell.name} stderr`).toBe('')
+        // Why: compat consumers gate the tool call on parseable stdout (#14818).
+        expect(result.stdout.trim(), `${shell.name} stdout`).toBe(provider.stdout)
+
+        const outsideOrca = await runHookCommand(
+          shell.executable,
+          shell.args,
+          hookEnvironment({ USERPROFILE: home, HOME: home })
+        )
+        expect(outsideOrca.timedOut, `${shell.name} outside Orca timed out`).toBe(false)
+        expect(outsideOrca.exitCode, `${shell.name} outside Orca exit code`).toBe(0)
+        expect(listener.posts).toHaveLength(before + 1)
+      }
+      // Why: two shell launches plus a real install can overrun the default under load.
+    },
+    60_000
+  )
 })
diff --git a/src/main/muse/hook-service.test.ts b/src/main/muse/hook-service.test.ts
index af04fc839e1..f25992d3221 100644
--- a/src/main/muse/hook-service.test.ts
+++ b/src/main/muse/hook-service.test.ts
@@ -1,10 +1,12 @@
-import { mkdirSync, mkdtempSync, readFileSync, rmSync, writeFileSync } from 'node:fs'
+import { mkdirSync, mkdtempSync, readFileSync, rmSync, statSync, writeFileSync } from 'node:fs'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
-import { afterEach, beforeEach, describe, expect, it } from 'vitest'
+import { afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
 import { parseMuseSettingsText } from './hook-config-json'
 import { MuseHookService } from './hook-service'
-import { MUSE_HOOK_EVENTS } from './hook-settings'
+import { MUSE_HOOK_EVENTS, buildMuseManagedHooksFile, getMuseManagedCommand } from './hook-settings'
+import { wrapWindowsHookCommand } from '../agent-hooks/windows-hook-command'
+import { createAgentHookMemorySftp } from '../agent-hooks/agent-hook-memory-sftp.test-fixture'
 
 // Why: getSharedManagedScriptPath() writes under homedir()/.orca and the
 // Muse config resolves via XDG_CONFIG_HOME ?? ~/.config/muse. Point HOME
@@ -13,9 +15,12 @@ import { MUSE_HOOK_EVENTS } from './hook-settings'
 let home: string
 let originalHome: string | undefined
 let originalXdg: string | undefined
+let originalProfile: string | undefined
 
 beforeEach(() => {
   home = mkdtempSync(join(tmpdir(), 'orca-muse-hook-'))
+  originalProfile = process.env.USERPROFILE
+  process.env.USERPROFILE = home
   originalHome = process.env.HOME
   originalXdg = process.env.XDG_CONFIG_HOME
   process.env.HOME = home
@@ -33,12 +38,24 @@ afterEach(() => {
   } else {
     process.env.XDG_CONFIG_HOME = originalXdg
   }
+  if (originalProfile === undefined) {
+    delete process.env.USERPROFILE
+  } else {
+    process.env.USERPROFILE = originalProfile
+  }
+  vi.restoreAllMocks()
   rmSync(home, { recursive: true, force: true })
 })
 
 const configPath = (): string => join(home, '.config', 'muse', 'settings.json')
 const managedHooksPath = (): string => join(home, '.orca', 'agent-hooks', 'muse-hooks.json')
-const scriptPath = (): string => join(home, '.orca', 'agent-hooks', 'muse-hook.sh')
+const scriptPath = (): string =>
+  join(
+    home,
+    '.orca',
+    'agent-hooks',
+    process.platform === 'win32' ? 'muse-hook.cmd' : 'muse-hook.sh'
+  )
 
 describe('MuseHookService', () => {
   it('reports not_installed before install', () => {
@@ -58,14 +75,16 @@ describe('MuseHookService', () => {
     expect(settings?.managed_hooks_env_vars).toContain('ORCA_PANE_KEY')
 
     const managedText = readFileSync(managedHooksPath(), 'utf-8')
-    expect(managedText).toContain('agent-hooks/muse-hook.sh')
+    expect(managedText).toContain(process.platform === 'win32' ? 'muse-hook.cmd' : 'muse-hook.sh')
     expect(MUSE_HOOK_EVENTS.every((event) => managedText.includes(`"${event}"`))).toBe(true)
     // The managed script must exist and POST to the muse hook endpoint.
     const script = readFileSync(scriptPath(), 'utf-8')
     expect(script).toContain('/hook/muse')
     // Why: payload is piped to curl via stdin so it never lands on the curl
     // command line (EDR oversized-command-line false positive).
-    expect(script).toContain('printf \'%s\' "$payload" | curl')
+    expect(script).toContain(
+      process.platform === 'win32' ? 'payload@-' : 'printf \'%s\' "$payload" | curl'
+    )
   })
 
   it('keeps user settings when installing, then drops only the pointer on remove', () => {
@@ -137,4 +156,57 @@ describe('MuseHookService', () => {
     expect(() => service.getStatus()).not.toThrow()
     expect(service.getStatus().state).toBe('partial')
   })
+
+  it.skipIf(process.platform !== 'win32')(
+    'upgrades encoded registrations once during refresh',
+    async () => {
+      const service = new MuseHookService()
+      service.install()
+      const settings = readFileSync(configPath(), 'utf8')
+      writeFileSync(
+        managedHooksPath(),
+        buildMuseManagedHooksFile(wrapWindowsHookCommand(scriptPath()))
+      )
+      await service.refreshManagedScripts()
+      const upgraded = readFileSync(managedHooksPath(), 'utf8')
+      expect(upgraded).toBe(buildMuseManagedHooksFile(getMuseManagedCommand(scriptPath())))
+      expect(upgraded).toContain(getMuseManagedCommand(scriptPath()))
+      const modified = statSync(managedHooksPath()).mtimeMs
+      await service.refreshManagedScripts()
+      expect(readFileSync(managedHooksPath(), 'utf8')).toBe(upgraded)
+      expect(statSync(managedHooksPath()).mtimeMs).toBe(modified)
+      expect(readFileSync(configPath(), 'utf8')).toBe(settings)
+      expect(service.getStatus().state).toBe('installed')
+    }
+  )
+
+  it('refresh never registers absent hooks or replaces a user-owned pointer', async () => {
+    const service = new MuseHookService()
+    await service.refreshManagedScripts()
+    expect(service.getStatus().state).toBe('not_installed')
+    service.install()
+    const managed = readFileSync(managedHooksPath(), 'utf8')
+    writeFileSync(configPath(), JSON.stringify({ managed_hooks_path: '/user/hooks.json' }))
+    await service.refreshManagedScripts()
+    expect(readFileSync(managedHooksPath(), 'utf8')).toBe(managed)
+    expect(
+      parseMuseSettingsText(readFileSync(configPath(), 'utf8'), 'test')?.managed_hooks_path
+    ).toBe('/user/hooks.json')
+  })
+
+  it('installs POSIX hooks on the SSH host even from a Windows client', async () => {
+    vi.spyOn(process, 'platform', 'get').mockReturnValue('win32')
+    const remote = createAgentHookMemorySftp()
+    const service = new MuseHookService()
+    expect((await service.installRemote(remote.sftp, '/home/alice smith')).state).toBe('installed')
+    const remoteHooksPath = '/home/alice smith/.orca/agent-hooks/muse-hooks.json'
+    const installed = remote.fs.files.get(remoteHooksPath)
+    expect(installed).toContain('/home/alice smith/.orca/agent-hooks/muse-hook.sh')
+    expect(installed).not.toMatch(/powershell|EncodedCommand|muse-hook.cmd/)
+    expect(remote.fs.files.get('/home/alice smith/.orca/agent-hooks/muse-hook.sh')).toContain(
+      '#!/bin/sh'
+    )
+    await service.installRemote(remote.sftp, '/home/alice smith')
+    expect(remote.fs.files.get(remoteHooksPath)).toBe(installed)
+  })
 })
diff --git a/src/main/muse/hook-service.ts b/src/main/muse/hook-service.ts
index 130e89fe0ca..3b9217ec3fc 100644
--- a/src/main/muse/hook-service.ts
+++ b/src/main/muse/hook-service.ts
@@ -33,7 +33,8 @@ import {
   getMuseRemoteManagedCommand,
   getMuseRemoteManagedHooksPath,
   MUSE_HOOK_EVENTS,
-  readManagedMuseHookEvents
+  readManagedMuseHookEvents,
+  refreshMuseManagedHooksFile
 } from './hook-settings'
 import {
   MUSE_MANAGED_HOOK_ENV_VARS,
@@ -145,7 +146,13 @@ function buildStatus(
 
 export class MuseHookService {
   async refreshManagedScripts(): Promise<void> {
-    await refreshManagedScriptIfPresent(getMuseManagedScriptPath(), getManagedScript())
+    const present = await refreshManagedScriptIfPresent(
+      getMuseManagedScriptPath(),
+      getManagedScript()
+    )
+    if (present && process.platform === 'win32') {
+      await refreshMuseManagedHooksFile()
+    }
   }
 
   getStatus(): AgentHookInstallStatus {
diff --git a/src/main/muse/hook-settings.test.ts b/src/main/muse/hook-settings.test.ts
new file mode 100644
index 00000000000..157a5ba28d9
--- /dev/null
+++ b/src/main/muse/hook-settings.test.ts
@@ -0,0 +1,39 @@
+import { afterEach, describe, expect, it, vi } from 'vitest'
+import { wrapWindowsHookCommand } from '../agent-hooks/windows-hook-command'
+import { wrapPosixHookCommand } from '../agent-hooks/posix-hook-command'
+import { getMuseManagedCommand, getMuseRemoteManagedCommand } from './hook-settings'
+
+afterEach(() => vi.restoreAllMocks())
+
+describe('Muse hook commands', () => {
+  it('dispatches safe Windows batch paths without PowerShell', () => {
+    vi.spyOn(process, 'platform', 'get').mockReturnValue('win32')
+    expect(getMuseManagedCommand('C:\\Users\\alice\\.orca\\agent-hooks\\muse-hook.cmd')).toBe(
+      'C:/Users/alice/.orca/agent-hooks/muse-hook.cmd'
+    )
+  })
+
+  it.each([
+    'C:\\Users\\Alice Smith\\.orca\\agent-hooks\\muse-hook.cmd',
+    'C:\\Users\\a&b\\.orca\\agent-hooks\\muse-hook.cmd',
+    'C:\\Users\\a%b\\.orca\\agent-hooks\\muse-hook.cmd',
+    "C:\\Users\\O'Brien\\.orca\\agent-hooks\\muse-hook.cmd",
+    'C:\\Users\\日本語\\.orca\\agent-hooks\\muse-hook.cmd',
+    '\\\\server\\share\\.orca\\agent-hooks\\muse-hook.cmd'
+  ])('retains the established quoting fallback for %s', (path) => {
+    vi.spyOn(process, 'platform', 'get').mockReturnValue('win32')
+    expect(getMuseManagedCommand(path)).toBe(wrapWindowsHookCommand(path))
+  })
+
+  it.each(['darwin', 'linux'] as const)('keeps local %s commands POSIX', (platform) => {
+    vi.spyOn(process, 'platform', 'get').mockReturnValue(platform)
+    const path = '/home/alice smith/.orca/agent-hooks/muse-hook.sh'
+    expect(getMuseManagedCommand(path)).toBe(wrapPosixHookCommand(path))
+  })
+
+  it('keeps SSH commands POSIX when the client runs Windows', () => {
+    vi.spyOn(process, 'platform', 'get').mockReturnValue('win32')
+    const path = '/home/alice smith/.orca/agent-hooks/muse-hook.sh'
+    expect(getMuseRemoteManagedCommand(path)).toBe(wrapPosixHookCommand(path))
+  })
+})
diff --git a/src/main/muse/hook-settings.ts b/src/main/muse/hook-settings.ts
index 0ef3d5d462b..98d208bd935 100644
--- a/src/main/muse/hook-settings.ts
+++ b/src/main/muse/hook-settings.ts
@@ -1,5 +1,6 @@
 import { homedir } from 'node:os'
 import { join } from 'node:path'
+import { readFile } from 'node:fs/promises'
 import {
   buildManagedCommandHook,
   createManagedCommandMatcher,
@@ -9,6 +10,9 @@ import {
   type HookDefinition
 } from '../agent-hooks/installer-utils'
 import { readManagedHookEventsFromJson } from '../agent-hooks/managed-hooks-json-events'
+import { wrapWindowsDirectCmdHookCommand } from '../agent-hooks/windows-direct-cmd-hook-command'
+import { refreshManagedScriptIfPresent } from '../agent-hooks/managed-hook-script-refresh'
+import { parseMuseSettingsText } from './hook-config-json'
 
 const MUSE_SCRIPT_BASE = 'muse-hook'
 
@@ -64,7 +68,7 @@ export function getMuseRemoteManagedHooksPath(remoteHome: string): string {
 
 export function getMuseManagedCommand(scriptPath: string): string {
   return process.platform === 'win32'
-    ? wrapWindowsHookCommand(scriptPath)
+    ? (wrapWindowsDirectCmdHookCommand(scriptPath) ?? wrapWindowsHookCommand(scriptPath))
     : wrapPosixHookCommand(scriptPath)
 }
 
@@ -83,6 +87,22 @@ export function buildMuseManagedHooksFile(command: string): string {
   return `${JSON.stringify({ hooks }, null, 2)}\n`
 }
 
+export async function refreshMuseManagedHooksFile(): Promise<void> {
+  const managedHooksPath = getMuseManagedHooksPath()
+  const [settings, existing] = await Promise.all([
+    readFile(getMuseConfigPath(), 'utf8').catch(() => null),
+    readFile(managedHooksPath, 'utf8').catch(() => null)
+  ])
+  const config = settings === null ? null : parseMuseSettingsText(settings, 'Muse settings.json')
+  if (!existing || config?.managed_hooks_path !== managedHooksPath) {
+    return
+  }
+  const next = buildMuseManagedHooksFile(getMuseManagedCommand(getMuseManagedScriptPath()))
+  if (existing !== next) {
+    await refreshManagedScriptIfPresent(managedHooksPath, next)
+  }
+}
+
 export function readManagedMuseHookEvents(
   parsed: unknown,
   isManagedCommand: (command: string | undefined) => boolean