diff --git a/src/integrations/claude-code/__tests__/run-powershell.spec.ts b/src/integrations/claude-code/__tests__/run-powershell.spec.ts
new file mode 100644
index 0000000000..daa5413532
--- /dev/null
+++ b/src/integrations/claude-code/__tests__/run-powershell.spec.ts
@@ -0,0 +1,333 @@
+import { describe, test, expect, vi, beforeEach, afterEach } from "vitest"
+
+// Mock i18n system
+vi.mock("../../../i18n", () => ({
+	t: vi.fn((key: string, options?: Record<string, any>) => {
+		if (key === "errors.claudeCode.notFound") {
+			const claudePath = options?.claudePath || "claude"
+			const installationUrl = options?.installationUrl || "https://docs.anthropic.com/en/docs/claude-code/setup"
+			const originalError = options?.originalError || "spawn claude ENOENT"
+			return `Claude Code executable '${claudePath}' not found.\n\nPlease install Claude Code CLI:\n1. Visit ${installationUrl} to download Claude Code\n2. Follow the installation instructions for your operating system\n3. Ensure the 'claude' command is available in your PATH\n4. Alternatively, configure a custom path in Roo settings under 'Claude Code Path'\n\nOriginal error: ${originalError}`
+		}
+		return key
+	}),
+}))
+
+// Mock os module
+const mockPlatform = vi.fn()
+vi.mock("os", () => ({
+	platform: mockPlatform,
+}))
+
+// Mock vscode workspace
+vi.mock("vscode", () => ({
+	workspace: {
+		workspaceFolders: [
+			{
+				uri: {
+					fsPath: "/test/workspace",
+				},
+			},
+		],
+	},
+}))
+
+// Mock execa
+const mockExeca = vi.fn()
+const mockStdin = {
+	write: vi.fn((data, encoding, callback) => {
+		if (callback) callback(null)
+	}),
+	end: vi.fn(),
+}
+
+const createMockProcess = () => {
+	let resolveProcess: (value: { exitCode: number }) => void
+	const processPromise = new Promise<{ exitCode: number }>((resolve) => {
+		resolveProcess = resolve
+	})
+
+	const mockProcess = {
+		stdin: mockStdin,
+		stdout: {
+			on: vi.fn(),
+		},
+		stderr: {
+			on: vi.fn(),
+		},
+		on: vi.fn((event, callback) => {
+			if (event === "close") {
+				setTimeout(() => {
+					callback(0)
+					resolveProcess({ exitCode: 0 })
+				}, 10)
+			}
+		}),
+		killed: false,
+		kill: vi.fn(),
+		then: processPromise.then.bind(processPromise),
+		catch: processPromise.catch.bind(processPromise),
+		finally: processPromise.finally.bind(processPromise),
+	}
+	return mockProcess
+}
+
+vi.mock("execa", () => ({
+	execa: mockExeca,
+}))
+
+// Mock readline
+let mockReadlineInterface: any = null
+
+vi.mock("readline", () => ({
+	default: {
+		createInterface: vi.fn(() => {
+			mockReadlineInterface = {
+				async *[Symbol.asyncIterator]() {
+					yield '{"type":"text","text":"PowerShell test response"}'
+					return
+				},
+				close: vi.fn(),
+			}
+			return mockReadlineInterface
+		}),
+	},
+}))
+
+describe("runClaudeCode - PowerShell Script Support", () => {
+	beforeEach(() => {
+		vi.clearAllMocks()
+		mockExeca.mockReturnValue(createMockProcess())
+		vi.spyOn(global, "setImmediate").mockImplementation((callback: any) => {
+			callback()
+			return {} as any
+		})
+		vi.resetModules()
+	})
+
+	afterEach(() => {
+		vi.restoreAllMocks()
+	})
+
+	test("should execute .ps1 files through PowerShell on Windows", async () => {
+		mockPlatform.mockReturnValue("win32")
+
+		const { runClaudeCode } = await import("../run")
+		const options = {
+			systemPrompt: "You are a helpful assistant",
+			messages: [{ role: "user" as const, content: "Hello" }],
+			path: "C:\\Users\\test\\AppData\\Local\\fnm_multishells\\52480_1754403777187\\claude.ps1",
+		}
+
+		const generator = runClaudeCode(options)
+		const results = []
+		for await (const chunk of generator) {
+			results.push(chunk)
+		}
+
+		// Verify PowerShell was called with correct arguments
+		const [executablePath, args] = mockExeca.mock.calls[0]
+		expect(executablePath).toBe("powershell.exe")
+		expect(args).toContain("-NoProfile")
+		expect(args).toContain("-ExecutionPolicy")
+		expect(args).toContain("Bypass")
+		expect(args).toContain("-File")
+		expect(args).toContain("C:\\Users\\test\\AppData\\Local\\fnm_multishells\\52480_1754403777187\\claude.ps1")
+		expect(args).toContain("-p")
+
+		// Verify the response was received (as parsed object, not string)
+		expect(results).toContainEqual({ type: "text", text: "PowerShell test response" })
+	})
+
+	test("should execute .PS1 files (uppercase) through PowerShell on Windows", async () => {
+		mockPlatform.mockReturnValue("win32")
+
+		const { runClaudeCode } = await import("../run")
+		const options = {
+			systemPrompt: "You are a helpful assistant",
+			messages: [{ role: "user" as const, content: "Hello" }],
+			path: "C:\\Program Files\\Claude\\claude.PS1",
+		}
+
+		const generator = runClaudeCode(options)
+		await generator.next()
+		await generator.return(undefined)
+
+		const [executablePath, args] = mockExeca.mock.calls[0]
+		expect(executablePath).toBe("powershell.exe")
+		expect(args).toContain("-File")
+		expect(args).toContain("C:\\Program Files\\Claude\\claude.PS1")
+	})
+
+	test("should not use PowerShell for .ps1 files on non-Windows platforms", async () => {
+		mockPlatform.mockReturnValue("darwin")
+
+		const { runClaudeCode } = await import("../run")
+		const options = {
+			systemPrompt: "You are a helpful assistant",
+			messages: [{ role: "user" as const, content: "Hello" }],
+			path: "/usr/local/bin/claude.ps1",
+		}
+
+		const generator = runClaudeCode(options)
+		await generator.next()
+		await generator.return(undefined)
+
+		// On non-Windows, should execute the file directly
+		const [executablePath] = mockExeca.mock.calls[0]
+		expect(executablePath).toBe("/usr/local/bin/claude.ps1")
+		expect(executablePath).not.toBe("powershell.exe")
+	})
+
+	test("should not use PowerShell for non-.ps1 files on Windows", async () => {
+		mockPlatform.mockReturnValue("win32")
+
+		const { runClaudeCode } = await import("../run")
+		const options = {
+			systemPrompt: "You are a helpful assistant",
+			messages: [{ role: "user" as const, content: "Hello" }],
+			path: "C:\\Program Files\\Claude\\claude.exe",
+		}
+
+		const generator = runClaudeCode(options)
+		await generator.next()
+		await generator.return(undefined)
+
+		// Should execute the .exe directly
+		const [executablePath] = mockExeca.mock.calls[0]
+		expect(executablePath).toBe("C:\\Program Files\\Claude\\claude.exe")
+		expect(executablePath).not.toBe("powershell.exe")
+	})
+
+	test("should handle PowerShell not found error gracefully", async () => {
+		mockPlatform.mockReturnValue("win32")
+
+		// Mock PowerShell not found error
+		const powershellError = new Error("spawn powershell.exe ENOENT")
+		;(powershellError as any).code = "ENOENT"
+		mockExeca.mockImplementationOnce(() => {
+			throw powershellError
+		})
+
+		const { runClaudeCode } = await import("../run")
+		const options = {
+			systemPrompt: "You are a helpful assistant",
+			messages: [{ role: "user" as const, content: "Hello" }],
+			path: "C:\\Users\\test\\claude.ps1",
+		}
+
+		const generator = runClaudeCode(options)
+
+		// Should throw a helpful error about PowerShell not being available
+		await expect(generator.next()).rejects.toThrow("PowerShell is not available or not in PATH")
+	})
+
+	test("should handle .ps1 script not found error with helpful message", async () => {
+		mockPlatform.mockReturnValue("win32")
+
+		// Mock script not found error (after PowerShell is found)
+		const mockProcessWithError = createMockProcess()
+		const scriptError = new Error("The system cannot find the file specified")
+
+		mockProcessWithError.on = vi.fn((event, callback) => {
+			if (event === "error") {
+				// This would happen if PowerShell runs but can't find the script
+				const enhancedError = new Error("spawn ENOENT")
+				;(enhancedError as any).code = "ENOENT"
+				callback(enhancedError)
+			}
+		})
+
+		// Mock readline to close immediately when there's an error
+		const mockReadlineForError = {
+			[Symbol.asyncIterator]() {
+				return {
+					async next() {
+						return { done: true, value: undefined }
+					},
+				}
+			},
+			close: vi.fn(),
+		}
+
+		const readline = await import("readline")
+		vi.mocked(readline.default.createInterface).mockReturnValueOnce(mockReadlineForError as any)
+		mockExeca.mockReturnValueOnce(mockProcessWithError)
+
+		const { runClaudeCode } = await import("../run")
+		const options = {
+			systemPrompt: "You are a helpful assistant",
+			messages: [{ role: "user" as const, content: "Hello" }],
+			path: "C:\\Users\\test\\nonexistent.ps1",
+		}
+
+		const generator = runClaudeCode(options)
+
+		// Should throw the standard Claude Code not found error
+		await expect(generator.next()).rejects.toThrow(/Claude Code executable.*not found/)
+	})
+
+	test("should pass model parameter correctly with PowerShell scripts", async () => {
+		mockPlatform.mockReturnValue("win32")
+
+		const { runClaudeCode } = await import("../run")
+		const options = {
+			systemPrompt: "You are a helpful assistant",
+			messages: [{ role: "user" as const, content: "Hello" }],
+			path: "C:\\claude.ps1",
+			modelId: "claude-3-5-sonnet-20241022",
+		}
+
+		const generator = runClaudeCode(options)
+		await generator.next()
+		await generator.return(undefined)
+
+		const [, args] = mockExeca.mock.calls[0]
+		expect(args).toContain("--model")
+		expect(args).toContain("claude-3-5-sonnet-20241022")
+	})
+
+	test("should pass maxOutputTokens correctly with PowerShell scripts", async () => {
+		mockPlatform.mockReturnValue("win32")
+
+		const { runClaudeCode } = await import("../run")
+		const options = {
+			systemPrompt: "You are a helpful assistant",
+			messages: [{ role: "user" as const, content: "Hello" }],
+			path: "C:\\claude.ps1",
+			maxOutputTokens: 8192,
+		}
+
+		const generator = runClaudeCode(options)
+		await generator.next()
+		await generator.return(undefined)
+
+		const [, , execOptions] = mockExeca.mock.calls[0]
+		expect(execOptions.env.CLAUDE_CODE_MAX_OUTPUT_TOKENS).toBe("8192")
+	})
+
+	test("should handle stdin correctly with PowerShell scripts on Windows", async () => {
+		mockPlatform.mockReturnValue("win32")
+
+		const { runClaudeCode } = await import("../run")
+		const messages = [{ role: "user" as const, content: "Test message" }]
+		const systemPrompt = "Test prompt"
+		const options = {
+			systemPrompt,
+			messages,
+			path: "C:\\claude.ps1",
+		}
+
+		const generator = runClaudeCode(options)
+		await generator.next()
+		await generator.return(undefined)
+
+		// On Windows with PowerShell, should pass both system prompt and messages via stdin
+		const expectedStdinData = JSON.stringify({ systemPrompt, messages })
+		expect(mockStdin.write).toHaveBeenCalledWith(expectedStdinData, "utf8", expect.any(Function))
+
+		// Should NOT have --system-prompt in args (passed via stdin instead)
+		const [, args] = mockExeca.mock.calls[0]
+		expect(args).not.toContain("--system-prompt")
+	})
+})
diff --git a/src/integrations/claude-code/run.ts b/src/integrations/claude-code/run.ts
index 3f438df0fc..da51ad0e73 100644
--- a/src/integrations/claude-code/run.ts
+++ b/src/integrations/claude-code/run.ts
@@ -37,6 +37,13 @@ export async function* runClaudeCode(
 	} catch (error: any) {
 		// Handle ENOENT errors immediately when spawning the process
 		if (error.code === "ENOENT" || error.message?.includes("ENOENT")) {
+			// Check if this is a PowerShell script error on Windows
+			const isWindows = os.platform() === "win32"
+			const isPowerShellScript = isWindows && claudePath.toLowerCase().endsWith(".ps1")
+			if (isPowerShellScript && error.message?.includes("powershell.exe")) {
+				// PowerShell itself is not found
+				throw new Error(`PowerShell is not available or not in PATH. Original error: ${error.message}`)
+			}
 			throw createClaudeCodeNotFoundError(claudePath, error)
 		}
 		throw error
@@ -65,7 +72,17 @@ export async function* runClaudeCode(
 		process.on("error", (err) => {
 			// Enhance ENOENT errors with helpful installation guidance
 			if (err.message.includes("ENOENT") || (err as any).code === "ENOENT") {
-				processState.error = createClaudeCodeNotFoundError(claudePath, err)
+				// Check if this is a PowerShell script error on Windows
+				const isWindows = os.platform() === "win32"
+				const isPowerShellScript = isWindows && claudePath.toLowerCase().endsWith(".ps1")
+				if (isPowerShellScript && err.message?.includes("powershell.exe")) {
+					// PowerShell itself is not found
+					processState.error = new Error(
+						`PowerShell is not available or not in PATH. Original error: ${err.message}`,
+					)
+				} else {
+					processState.error = createClaudeCodeNotFoundError(claudePath, err)
+				}
 			} else {
 				processState.error = err
 			}
@@ -153,8 +170,22 @@ function runProcess({
 	const claudePath = path || "claude"
 	const isWindows = os.platform() === "win32"
 
+	// Check if the path is a PowerShell script on Windows
+	const isPowerShellScript = isWindows && claudePath.toLowerCase().endsWith(".ps1")
+
 	// Build args based on platform
-	const args = ["-p"]
+	let executablePath: string
+	let args: string[]
+
+	if (isPowerShellScript) {
+		// For PowerShell scripts on Windows, execute through PowerShell
+		executablePath = "powershell.exe"
+		args = ["-NoProfile", "-ExecutionPolicy", "Bypass", "-File", claudePath, "-p"]
+	} else {
+		// For regular executables
+		executablePath = claudePath
+		args = ["-p"]
+	}
 
 	// Pass system prompt as flag on non-Windows, via stdin on Windows (avoids cmd length limits)
 	if (!isWindows) {
@@ -176,7 +207,7 @@ function runProcess({
 		args.push("--model", modelId)
 	}
 
-	const child = execa(claudePath, args, {
+	const child = execa(executablePath, args, {
 		stdin: "pipe",
 		stdout: "pipe",
 		stderr: "pipe",