diff --git a/src/main/ipc/hooks/register-worktree-hook-check-handler.ts b/src/main/ipc/hooks/register-worktree-hook-check-handler.ts
index 64296ccb068..4547bcfad5d 100644
--- a/src/main/ipc/hooks/register-worktree-hook-check-handler.ts
+++ b/src/main/ipc/hooks/register-worktree-hook-check-handler.ts
@@ -3,6 +3,7 @@ import { getRepoDialableSshTargetId, type ExecutionHostId } from '../../../share
 import { isFolderRepo } from '../../../shared/repo-kind'
 import { hasHooksFile, loadHooks, hasUnrecognizedOrcaYamlKeys } from '../../hooks'
 import { resolveRepoForExecutionHost } from '../worktrees/repo-host-ownership'
+import { blockedWslDistroForPath } from '../../wsl/wsl-unc-access-gate'
 import type { WorktreeIpcContext } from '../worktrees/worktree-ipc-context'
 
 export function registerWorktreeHookCheckHandler(context: WorktreeIpcContext): void {
@@ -10,7 +11,7 @@ export function registerWorktreeHookCheckHandler(context: WorktreeIpcContext): v
 
   ipcMain.handle(
     'hooks:check',
-    async (_event, args: { repoId: string; hostId?: ExecutionHostId }) => {
+    async (_event, args: { repoId: string; hostId?: ExecutionHostId; background?: boolean }) => {
       const repo = resolveRepoForExecutionHost(store, args.repoId, args.hostId)
       if (!repo) {
         const repoIdExists = store.getRepos().some((candidate) => candidate.id === args.repoId)
@@ -35,6 +36,11 @@ export function registerWorktreeHookCheckHandler(context: WorktreeIpcContext): v
         }
       }
 
+      // A render-driven check must not open a stopped distro's `\\wsl.localhost` paths (E9).
+      if (args.background && (await blockedWslDistroForPath(repo.path))) {
+        return { status: 'error', hasHooks: false, hooks: null, mayNeedUpdate: false }
+      }
+
       const has = hasHooksFile(repo.path)
       const hooks = has ? loadHooks(repo.path) : null
       // Well-formed unknown keys may come from a newer Orca; suggest updating instead of parse repair.
diff --git a/src/main/ipc/hooks/worktree-hook-check-background-gate.test.ts b/src/main/ipc/hooks/worktree-hook-check-background-gate.test.ts
new file mode 100644
index 00000000000..61b930ea874
--- /dev/null
+++ b/src/main/ipc/hooks/worktree-hook-check-background-gate.test.ts
@@ -0,0 +1,65 @@
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+import type { Repo } from '../../../shared/repo-types'
+
+const mocks = vi.hoisted(() => ({
+  handlers: new Map<string, (event: unknown, args: unknown) => unknown>(),
+  hasHooksFile: vi.fn((_path: string) => false),
+  blocked: vi.fn<(path: string) => Promise<{ distro: string; state: 'stopped' } | null>>()
+}))
+
+vi.mock('electron', () => ({
+  ipcMain: {
+    handle: (channel: string, handler: (event: unknown, args: unknown) => unknown) =>
+      mocks.handlers.set(channel, handler)
+  }
+}))
+vi.mock('../../hooks', () => ({
+  hasHooksFile: mocks.hasHooksFile,
+  loadHooks: () => null,
+  hasUnrecognizedOrcaYamlKeys: () => false
+}))
+vi.mock('../../wsl/wsl-unc-access-gate', () => ({ blockedWslDistroForPath: mocks.blocked }))
+
+import { registerWorktreeHookCheckHandler } from './register-worktree-hook-check-handler'
+
+const UNC = String.raw`\\wsl.localhost\Ubuntu\home\u\app`
+
+function check(args: { background?: boolean }) {
+  const repo: Partial<Repo> = { id: 'repo', path: UNC, kind: 'git', executionHostId: 'local' }
+  const store = { getRepos: () => [repo], getRepo: () => repo }
+  // oxlint-disable-next-line typescript/consistent-type-assertions -- SAFETY: The handler reads only these store accessors.
+  registerWorktreeHookCheckHandler({ store } as never)
+  return mocks.handlers.get('hooks:check')!(null, { repoId: 'repo', ...args })
+}
+
+describe('hooks:check on a stopped WSL distro', () => {
+  beforeEach(() => {
+    mocks.hasHooksFile.mockClear()
+    mocks.blocked.mockReset()
+    mocks.blocked.mockResolvedValue({ distro: 'Ubuntu', state: 'stopped' })
+  })
+
+  it('refuses a background check without opening orca.yaml, so it cannot boot the distro', async () => {
+    await expect(check({ background: true })).resolves.toEqual({
+      status: 'error',
+      hasHooks: false,
+      hooks: null,
+      mayNeedUpdate: false
+    })
+    expect(mocks.blocked).toHaveBeenCalledWith(UNC)
+    expect(mocks.hasHooksFile).not.toHaveBeenCalled()
+  })
+
+  it('still reads for a launch, which is a user act that starts the distro anyway', async () => {
+    await expect(check({})).resolves.toMatchObject({ status: 'ok' })
+    expect(mocks.blocked).not.toHaveBeenCalled()
+    expect(mocks.hasHooksFile).toHaveBeenCalledWith(UNC)
+  })
+
+  it('reads a running distro for a background check as before', async () => {
+    mocks.blocked.mockResolvedValue(null)
+
+    await expect(check({ background: true })).resolves.toMatchObject({ status: 'ok' })
+    expect(mocks.hasHooksFile).toHaveBeenCalledWith(UNC)
+  })
+})
diff --git a/src/preload/api/agent-hook-api.ts b/src/preload/api/agent-hook-api.ts
index db222d45332..c67a40ecb8a 100644
--- a/src/preload/api/agent-hook-api.ts
+++ b/src/preload/api/agent-hook-api.ts
@@ -3,7 +3,8 @@ import type { ExecutionHostId } from '../../shared/execution-host'
 import type { SetupScriptImportCandidate } from '../../shared/setup-script-imports'
 
 export type HooksApi = {
-  check: (args: { repoId: string; hostId?: ExecutionHostId }) => Promise<{
+  /** `background`: a render-driven probe, refused (status 'error') rather than booting a stopped WSL distro. */
+  check: (args: { repoId: string; hostId?: ExecutionHostId; background?: boolean }) => Promise<{
     status?: 'ok' | 'error'
     hasHooks: boolean
     hooks: OrcaHooks | null
diff --git a/src/preload/api/hooks-bridge.ts b/src/preload/api/hooks-bridge.ts
index a4d846d235d..6c32f026125 100644
--- a/src/preload/api/hooks-bridge.ts
+++ b/src/preload/api/hooks-bridge.ts
@@ -3,7 +3,7 @@ import type { ExecutionHostId } from '../../shared/execution-host'
 import type { PreloadApi } from '../api-types'
 
 export const hooksApi = {
-  check: (args: { repoId: string; hostId?: ExecutionHostId }) =>
+  check: (args: { repoId: string; hostId?: ExecutionHostId; background?: boolean }) =>
     ipcRenderer.invoke('hooks:check', args),
 
   inspectSetupScriptImports: (args: { repoId: string; hostId?: ExecutionHostId }) =>
diff --git a/src/renderer/src/components/setup-guide/use-setup-guide-progress.ts b/src/renderer/src/components/setup-guide/use-setup-guide-progress.ts
index 7bb59f7fcac..5d82f43ab90 100644
--- a/src/renderer/src/components/setup-guide/use-setup-guide-progress.ts
+++ b/src/renderer/src/components/setup-guide/use-setup-guide-progress.ts
@@ -169,9 +169,9 @@ export function useSetupGuideProgress(
 
     async function refreshSetupScriptState(): Promise<void> {
       for (const repo of orderedGitRepos) {
-        const hooksResult = await checkRuntimeHooks(getRepoExecutionHostId(repo), repo.id).catch(
-          () => null
-        )
+        const hooksResult = await checkRuntimeHooks(getRepoExecutionHostId(repo), repo.id, {
+          background: true
+        }).catch(() => null)
         if (stale) {
           return
         }
diff --git a/src/renderer/src/components/sidebar/SetupScriptPromptCard.tsx b/src/renderer/src/components/sidebar/SetupScriptPromptCard.tsx
index f5f832edecf..367a65185b9 100644
--- a/src/renderer/src/components/sidebar/SetupScriptPromptCard.tsx
+++ b/src/renderer/src/components/sidebar/SetupScriptPromptCard.tsx
@@ -75,7 +75,7 @@ function SetupScriptPromptCard(): React.JSX.Element | null {
       const hostId = getRepoExecutionHostId(repo)
       const inspection = await inspectSetupScriptPromptState({
         repo,
-        checkHooks: () => checkRuntimeHooks(hostId, repo.id),
+        checkHooks: () => checkRuntimeHooks(hostId, repo.id, { background: true }),
         inspectImports: () => inspectRuntimeSetupScriptImports(hostId, repo.id)
       })
       if (!cancelled) {
diff --git a/src/renderer/src/runtime/runtime-hooks-client.test.ts b/src/renderer/src/runtime/runtime-hooks-client.test.ts
index 31e3c1c6bd6..c44725672e1 100644
--- a/src/renderer/src/runtime/runtime-hooks-client.test.ts
+++ b/src/renderer/src/runtime/runtime-hooks-client.test.ts
@@ -73,6 +73,18 @@ describe('runtime hooks client', () => {
     expect(runtimeEnvironmentCall).not.toHaveBeenCalled()
   })
 
+  it('marks a render-driven check as background, so a stopped WSL distro is refused, not booted', async () => {
+    hooksCheck.mockResolvedValue({ hasHooks: false, hooks: null, mayNeedUpdate: false })
+
+    await checkRuntimeHooks('local', 'repo-1', { background: true })
+
+    expect(hooksCheck).toHaveBeenLastCalledWith({
+      repoId: 'repo-1',
+      hostId: 'local',
+      background: true
+    })
+  })
+
   it('routes hook operations through the repo owner runtime environment', async () => {
     runtimeEnvironmentCall.mockResolvedValue({
       id: 'rpc-1',
diff --git a/src/renderer/src/runtime/runtime-hooks-client.ts b/src/renderer/src/runtime/runtime-hooks-client.ts
index f24af0e6ade..54624230172 100644
--- a/src/renderer/src/runtime/runtime-hooks-client.ts
+++ b/src/renderer/src/runtime/runtime-hooks-client.ts
@@ -30,13 +30,19 @@ export type IssueCommandReadResult = {
   source: 'local' | 'shared' | 'none'
 }
 
+/** `background`: a render-driven probe that must not boot a stopped WSL distro (E9); launches omit it. */
 export async function checkRuntimeHooks(
   hostId: ExecutionHostId,
-  repoId: string
+  repoId: string,
+  options: { background?: boolean } = {}
 ): Promise<HookCheckResult> {
   const target = getHookInspectionTarget(hostId)
   if (target.kind !== 'environment') {
-    return window.api.hooks.check({ repoId, hostId })
+    return window.api.hooks.check({
+      repoId,
+      hostId,
+      ...(options.background ? { background: true } : {})
+    })
   }
   return callRuntimeRpc<HookCheckResult>(
     target,