diff --git a/.github/workflows/windows-recovery.yml b/.github/workflows/windows-recovery.yml
index 3350f66f66b..39edb6a05a7 100644
--- a/.github/workflows/windows-recovery.yml
+++ b/.github/workflows/windows-recovery.yml
@@ -73,6 +73,7 @@ on:
       - 'packages/runtime-host/src/__tests__/skill-catalog-repository.test.ts'
       - 'packages/runtime-host/src/__tests__/skill-catalog-transaction.test.ts'
       - 'packages/runtime-host/src/__tests__/skill-catalog-two-client-uds.test.ts'
+      - 'packages/runtime-host/src/__tests__/ssh-operator-activation.test.ts'
       - 'packages/runtime-host/src/assistant/proactive-matters/files.ts'
       - 'packages/runtime-host/src/client/client-instance-identity.ts'
       - 'packages/runtime-host/src/client/host-profile.ts'
@@ -220,6 +221,13 @@ jobs:
           node.exe --test packages/runtime-host/dist/__tests__/control-endpoint.test.js
           ./scripts/windows-runtime-host-local-ipc-trust.ps1
 
+      # The POSIX command execution case in this suite requires a POSIX host.
+      - name: Verify Windows SSH operator arguments and activation
+        shell: pwsh
+        run: >-
+          node.exe --test --test-name-pattern="Windows SSH operator|SSH activation"
+          packages/runtime-host/dist/__tests__/ssh-operator-activation.test.js
+
       - name: Verify Skill catalog on Windows
         shell: pwsh
         run: |
diff --git a/packages/runtime-host/src/__tests__/ssh-operator-activation.test.ts b/packages/runtime-host/src/__tests__/ssh-operator-activation.test.ts
index 927423add19..d2f7ee69c3c 100644
--- a/packages/runtime-host/src/__tests__/ssh-operator-activation.test.ts
+++ b/packages/runtime-host/src/__tests__/ssh-operator-activation.test.ts
@@ -18,7 +18,7 @@
  */
 
 import assert from 'node:assert/strict';
-import { execFile } from 'node:child_process';
+import { execFile, spawnSync } from 'node:child_process';
 import { mkdtemp, rm, writeFile } from 'node:fs/promises';
 import { tmpdir } from 'node:os';
 import { join } from 'node:path';
@@ -58,6 +58,61 @@ const operator = (modulePath: string) => ({
   modulePath,
 });
 
+test('Windows SSH operator preserves native argv, environment, output and exit status', {
+  skip: process.platform !== 'win32',
+}, async (t) => {
+  const directory = await mkdtemp(join(tmpdir(), 'maka-operator-'));
+  t.after(() => rm(directory, { recursive: true, force: true }));
+  const modulePath = join(directory, 'operator 中文.mjs');
+  await writeFile(
+    modulePath,
+    `import { readFileSync } from 'node:fs';process.stdout.write(JSON.stringify({args:process.argv.slice(2),env:process.env.MAKA_TEST_VALUE,stdin:readFileSync(0,'utf8')}));process.stderr.write('diagnostic');process.exitCode=37;`,
+  );
+  const args = [
+    'configure',
+    '--project-root-json',
+    JSON.stringify({ label: 'My project', path: 'C:\\项目\\' }),
+    '',
+    'space and trailing slash\\',
+    'embedded"quote',
+    'backslash\\"quote',
+    '%PATH%',
+    '!PATH!',
+    '&|<>',
+  ];
+  const environment = { MAKA_TEST_VALUE: 'literal "value" 中文' };
+  const command = runtimeHostSshOperatorRemoteCommand(
+    {
+      kind: 'node',
+      platform: 'win32',
+      nodePath: process.execPath,
+      modulePath,
+    },
+    args,
+    environment,
+  );
+  const encoded = command.split(' -EncodedCommand ')[1];
+  assert.ok(encoded);
+  const result = spawnSync(
+    'powershell.exe',
+    ['-NoLogo', '-NoProfile', '-NonInteractive', '-EncodedCommand', encoded],
+    {
+      encoding: 'utf8',
+      input: 'operator input 中文\n',
+      windowsHide: true,
+      timeout: 15_000,
+    },
+  );
+  assert.ifError(result.error);
+  assert.equal(result.status, 37, result.stderr);
+  assert.equal(result.stderr, 'diagnostic');
+  assert.deepEqual(JSON.parse(result.stdout), {
+    args,
+    env: environment.MAKA_TEST_VALUE,
+    stdin: 'operator input 中文\n',
+  });
+});
+
 test('SSH activation accepts a strict final frame that drains after process exit', async () => {
   let invocation: Parameters<RuntimeHostSshOperatorProcessFactory>[0] | undefined;
   const result = await activateRuntimeHostSshOperator(
diff --git a/packages/runtime-host/src/client/ssh-operator-activation.ts b/packages/runtime-host/src/client/ssh-operator-activation.ts
index 3f49f217cf6..cdd22512187 100644
--- a/packages/runtime-host/src/client/ssh-operator-activation.ts
+++ b/packages/runtime-host/src/client/ssh-operator-activation.ts
@@ -146,7 +146,10 @@ export function runtimeHostSshOperatorRemoteCommand(
   if (operator.kind !== 'node') throw new Error('Windows Runtime Host operator must use Node');
   const payload = Buffer.from(
     JSON.stringify({
-      ...invocation,
+      executable: invocation.executable,
+      // ProcessStartInfo bypasses Windows PowerShell 5.1's lossy native argument
+      // binder. Encode the argv using the Windows C runtime quoting rules.
+      argumentLine: invocation.args.map(quoteWindowsArgument).join(' '),
       environment,
       modulePath: operator.modulePath,
       deploymentRoot: win32.dirname(operator.modulePath),
@@ -155,17 +158,22 @@ export function runtimeHostSshOperatorRemoteCommand(
     'utf8',
   ).toString('base64');
   const script = [
+    `$ProgressPreference='SilentlyContinue'`,
     `$p=[Text.Encoding]::UTF8.GetString([Convert]::FromBase64String('${payload}'))|ConvertFrom-Json`,
     `if($p.missingOperatorIsSuccess -and -not (Test-Path -LiteralPath $p.modulePath -PathType Leaf)){if(-not (Test-Path -LiteralPath $p.deploymentRoot)){exit 0}else{exit 1}}`,
     `foreach($e in $p.environment.psobject.Properties){[Environment]::SetEnvironmentVariable($e.Name,[string]$e.Value,'Process')}`,
     `$code=1`,
-    `try{& ([string]$p.executable) @($p.args|ForEach-Object {[string]$_});$code=if($null -eq $LASTEXITCODE){1}else{$LASTEXITCODE}}catch{$code=1}`,
+    `try{$start=New-Object System.Diagnostics.ProcessStartInfo;$start.FileName=[string]$p.executable;$start.Arguments=[string]$p.argumentLine;$start.UseShellExecute=$false;$child=[System.Diagnostics.Process]::Start($start);try{$child.WaitForExit();$code=$child.ExitCode}finally{$child.Dispose()}}catch{$code=1}`,
     `exit $code`,
   ].join(';');
   const encoded = Buffer.from(script, 'utf16le').toString('base64');
   return `powershell.exe -NoLogo -NoProfile -NonInteractive -EncodedCommand ${encoded}`;
 }
 
+function quoteWindowsArgument(value: string): string {
+  return `"${value.replace(/(\\*)"/gu, '$1$1\\"').replace(/(\\+)$/u, '$1$1')}"`;
+}
+
 async function waitForActivation(
   child: RuntimeHostSshOperatorProcess,
   input: RuntimeHostSshOperatorActivationInput,