diff --git a/packages/cli/src/commands/daemon/status.ts b/packages/cli/src/commands/daemon/status.ts
index 132fe4876..d37194100 100644
--- a/packages/cli/src/commands/daemon/status.ts
+++ b/packages/cli/src/commands/daemon/status.ts
@@ -1,7 +1,12 @@
 import type { Command } from "commander";
 import { execFileSync } from "node:child_process";
 import { createRequire } from "node:module";
-import { getOrCreateServerId, findExecutable, applyProviderEnv } from "@getpaseo/server";
+import {
+  getOrCreateServerId,
+  findExecutable,
+  quoteWindowsCommand,
+  applyProviderEnv,
+} from "@getpaseo/server";
 import { tryConnectToDaemon } from "../../utils/client.js";
 import type { CommandOptions, ListResult, OutputSchema } from "../../output/index.js";
 import { resolveLocalDaemonState, resolveTcpHostFromListen } from "./local-daemon.js";
@@ -170,7 +175,7 @@ function checkProviderBinary(binary: string): { path: string | null; version: st
   }
   const env = applyProviderEnv(process.env);
   try {
-    const output = execFileSync(binaryPath, ["--version"], {
+    const output = execFileSync(quoteWindowsCommand(binaryPath), ["--version"], {
       encoding: "utf8",
       timeout: 5000,
       stdio: ["ignore", "pipe", "pipe"],
diff --git a/packages/server/src/server/agent/provider-launch-config.test.ts b/packages/server/src/server/agent/provider-launch-config.test.ts
index 6ce4ca983..962313963 100644
--- a/packages/server/src/server/agent/provider-launch-config.test.ts
+++ b/packages/server/src/server/agent/provider-launch-config.test.ts
@@ -1,7 +1,8 @@
-import { beforeEach, describe, expect, test, vi } from "vitest";
+import { afterEach, beforeEach, describe, expect, test, vi } from "vitest";
 
 import {
   findExecutable,
+  quoteWindowsCommand,
   resolveProviderCommandPrefix,
   applyProviderEnv,
   type ProviderRuntimeSettings,
@@ -218,3 +219,39 @@ describe("findExecutable", () => {
     expect(findExecutableDependencies.existsSync).toHaveBeenCalledWith("/usr/local/bin/codex");
   });
 });
+
+describe("quoteWindowsCommand", () => {
+  const originalPlatform = process.platform;
+
+  function setPlatform(value: string) {
+    Object.defineProperty(process, "platform", { value, writable: true });
+  }
+
+  afterEach(() => {
+    setPlatform(originalPlatform);
+  });
+
+  test("quotes a Windows path with spaces", () => {
+    setPlatform("win32");
+    expect(quoteWindowsCommand("C:\\Program Files\\Anthropic\\claude.exe")).toBe(
+      '"C:\\Program Files\\Anthropic\\claude.exe"',
+    );
+  });
+
+  test("does not double-quote an already-quoted path", () => {
+    setPlatform("win32");
+    expect(quoteWindowsCommand('"C:\\Program Files\\Anthropic\\claude.exe"')).toBe(
+      '"C:\\Program Files\\Anthropic\\claude.exe"',
+    );
+  });
+
+  test("returns the command unchanged when there are no spaces", () => {
+    setPlatform("win32");
+    expect(quoteWindowsCommand("C:\\nvm4w\\nodejs\\codex")).toBe("C:\\nvm4w\\nodejs\\codex");
+  });
+
+  test("returns the command unchanged on non-Windows platforms", () => {
+    setPlatform("darwin");
+    expect(quoteWindowsCommand("/usr/local/bin/claude code")).toBe("/usr/local/bin/claude code");
+  });
+});
diff --git a/packages/server/src/server/agent/provider-launch-config.ts b/packages/server/src/server/agent/provider-launch-config.ts
index 267c3bd8d..ba5260082 100644
--- a/packages/server/src/server/agent/provider-launch-config.ts
+++ b/packages/server/src/server/agent/provider-launch-config.ts
@@ -273,6 +273,19 @@ export function findExecutable(
   }
 }
 
+/**
+ * When spawning with `shell: true` on Windows, the command is passed to
+ * `cmd.exe /d /s /c "command args"`. The `/s` strips outer quotes, so a
+ * command path with spaces (e.g. `C:\Program Files\...`) is split at the
+ * space. Wrapping it in quotes produces the correct `"C:\Program Files\..." args`.
+ */
+export function quoteWindowsCommand(command: string): string {
+  if (process.platform !== "win32") return command;
+  if (!command.includes(" ")) return command;
+  if (command.startsWith('"') && command.endsWith('"')) return command;
+  return `"${command}"`;
+}
+
 export function isCommandAvailable(command: string): boolean {
   return findExecutable(command) !== null;
 }
diff --git a/packages/server/src/server/agent/providers/claude-agent.ts b/packages/server/src/server/agent/providers/claude-agent.ts
index 3b05dc5db..00352f65d 100644
--- a/packages/server/src/server/agent/providers/claude-agent.ts
+++ b/packages/server/src/server/agent/providers/claude-agent.ts
@@ -70,6 +70,7 @@ import type {
 import {
   applyProviderEnv,
   findExecutable,
+  quoteWindowsCommand,
   type ProviderRuntimeSettings,
 } from "../provider-launch-config.js";
 import { getOrchestratorModeInstructions } from "../orchestrator-instructions.js";
@@ -213,7 +214,7 @@ function applyRuntimeSettingsToClaudeOptions(
       const isDefaultRuntime =
         resolved.command === "node" || resolved.command === "bun";
       const command = isDefaultRuntime ? process.execPath : resolved.command;
-      const child = spawn(command, resolved.args, {
+      const child = spawn(quoteWindowsCommand(command), resolved.args, {
         cwd: spawnOptions.cwd,
         env: {
           ...applyProviderEnv(spawnOptions.env, runtimeSettings),
diff --git a/packages/server/src/server/agent/providers/codex-app-server-agent.ts b/packages/server/src/server/agent/providers/codex-app-server-agent.ts
index ccd83cf8c..dd96e74e0 100644
--- a/packages/server/src/server/agent/providers/codex-app-server-agent.ts
+++ b/packages/server/src/server/agent/providers/codex-app-server-agent.ts
@@ -42,6 +42,7 @@ import {
 import {
   applyProviderEnv,
   findExecutable,
+  quoteWindowsCommand,
   resolveProviderCommandPrefix,
   type ProviderRuntimeSettings,
 } from "../provider-launch-config.js";
@@ -3419,7 +3420,7 @@ export class CodexAppServerAgentClient implements AgentClient {
       },
       "Spawning Codex app server",
     );
-    return spawn(launchPrefix.command, [...launchPrefix.args, "app-server"], {
+    return spawn(quoteWindowsCommand(launchPrefix.command), [...launchPrefix.args, "app-server"], {
       detached: process.platform !== "win32",
       shell: process.platform === "win32",
       stdio: ["pipe", "pipe", "pipe"],
diff --git a/packages/server/src/server/agent/providers/opencode-agent.ts b/packages/server/src/server/agent/providers/opencode-agent.ts
index a129675d4..8764b0df4 100644
--- a/packages/server/src/server/agent/providers/opencode-agent.ts
+++ b/packages/server/src/server/agent/providers/opencode-agent.ts
@@ -32,6 +32,7 @@ import type {
 import {
   applyProviderEnv,
   findExecutable,
+  quoteWindowsCommand,
   resolveProviderCommandPrefix,
   type ProviderRuntimeSettings,
 } from "../provider-launch-config.js";
@@ -333,7 +334,7 @@ export class OpenCodeServerManager {
 
     return new Promise((resolve, reject) => {
       this.server = spawn(
-        launchPrefix.command,
+        quoteWindowsCommand(launchPrefix.command),
         [...launchPrefix.args, "serve", "--port", String(this.port)],
         {
           shell: process.platform === "win32",
diff --git a/packages/server/src/server/exports.ts b/packages/server/src/server/exports.ts
index a7e2bb8fc..3a4a110ea 100644
--- a/packages/server/src/server/exports.ts
+++ b/packages/server/src/server/exports.ts
@@ -30,7 +30,11 @@ export {
 } from "./speech/providers/local/sherpa/sherpa-runtime-env.js";
 
 // Provider binary resolution
-export { findExecutable, applyProviderEnv } from "./agent/provider-launch-config.js";
+export {
+  findExecutable,
+  applyProviderEnv,
+  quoteWindowsCommand,
+} from "./agent/provider-launch-config.js";
 
 // Agent SDK types for CLI commands
 export type {