How to Set Up MCP Servers in Claude Desktop on Windows (2026 Guide)

To add an MCP server to Claude Desktop on Windows, you have two routes. The easy one is a desktop extension: open the Extensions area in Settings, pick a server and click Install. The manual one is editing %APPDATA%\Claude\claude_desktop_config.json, then fully quitting and reopening Claude.

Remote servers that live on the internet use a third route, custom connectors, which do not touch your Windows files at all. This guide covers all three, plus the Windows-specific problems that cause most failed setups.

Checked against: the MCP project's local server guide, Anthropic's desktop extensions article and Anthropic's custom connector article on 2 November 2026.

Before you start

• Claude Desktop for Windows. The download page offers x64 and arm64 installers, and lists the app in the Microsoft Store.
• Node.js (for manual servers). Many servers start with npx, which ships with Node.js. Check it with node --version in Command Prompt or PowerShell. The MCP guide recommends the LTS version.
• Python and uv (for some servers). Servers started with uvx need Astral's uv tool installed.

Route 1: Install a desktop extension

Anthropic describes desktop extensions as local MCP servers you can install "as easily as browser extensions." The steps from its support article:

1. Open Settings, then Desktop app, and select Manage next to Extensions. Older layouts use Settings > Extensions.
2. Click Browse extensions and choose an Anthropic-reviewed extension.
3. Click Install and fill in any settings, such as an API key.

To install a .mcpb file someone sent you, open the same area, click Advanced settings, find the Extension Developer section and click Install Extension.... Anthropic says fields marked sensitive are stored in Windows Credential Manager, not in plain text. Our guide to MCP desktop extensions (.mcpb) explains the format.

Route 2: Edit claude_desktop_config.json

Use this when a server has no extension, or you need custom arguments.

1. In Claude, open Settings, then the Developer tab, and click Edit Config.
2. Replace or merge the contents with your server block (example below).
3. Save the file.
4. Quit Claude from the system tray icon, not just the window, and reopen it.

This Windows example, from the MCP quickstart, gives the official Filesystem server access to two folders:

{
  "mcpServers": {
    "filesystem": {
      "command": "npx",
      "args": [
        "-y",
        "@modelcontextprotocol/server-filesystem",
        "C:\\Users\\username\\Desktop",
        "C:\\Users\\username\\Downloads"
      ]
    }
  }
}

Replace username with your Windows user name. Each \ becomes \\ because JSON treats a single backslash as an escape character. Checked against the MCP quickstart on 2 November 2026. You can also generate the block with our free MCP config generator.

Route 3: Add a remote server as a custom connector

If the vendor gives you a URL such as https://mcp.example.com/mcp, you do not need the JSON file. Anthropic's connector article says Pro and Max users go to Customize > Connectors, click + Add, then Add custom connector. On Team and Enterprise, Owners add it in Organization settings > Connectors first.

Anthropic notes that "Free users are limited to one custom connector." It also says Claude connects "from Anthropic's cloud infrastructure, rather than from your local device." So a server on your office network must allowlist Anthropic's IP addresses.

Windows problems and fixes

npx or uvx is "not found"

Claude Desktop starts servers itself, outside your terminal. If npx works in PowerShell but not in Claude, use the full path to the executable in command, or reinstall Node.js so it is on the system PATH. Our spawn npx ENOENT fix covers this error in depth.

${APPDATA} appears in an error

The MCP guide has a specific fix. If a server log shows ${APPDATA} inside a path, add the expanded value to that server's env:

{
  "brave-search": {
    "command": "npx",
    "args": ["-y", "@modelcontextprotocol/server-brave-search"],
    "env": {
      "APPDATA": "C:\\Users\\user\\AppData\\Roaming\\",
      "BRAVE_API_KEY": "..."
    }
  }
}

The same guide says npx may keep failing if npm is not installed globally. It suggests checking that %APPDATA%\npm exists, and running npm install -g npm if not.

Your edits do nothing (Microsoft Store install)

In GitHub issue #26073, opened in February 2026 and still open on 2 November 2026, users report that Store (MSIX) installs read %LOCALAPPDATA%\Packages\Claude_<id>\LocalCache\Roaming\Claude\claude_desktop_config.json, while Edit Config opens the %APPDATA% copy. Anthropic has not responded in the thread. Check for that second file and edit it if it exists. Our config file location guide has the details.

How to verify the server loaded

1. Restart Claude Desktop fully.
2. Click the "Add files, connectors, and more" button at the bottom left of the message box.
3. Hover over Connectors, then click Manage connectors. Your server and its tools should be listed.

If it is missing, read the logs. In Command Prompt, run:

type "%APPDATA%\Claude\logs\mcp*.log"

mcp.log records connection failures, and mcp-server-NAME.log holds the server's own error output. You can also run the server's command directly in a terminal, for example npx -y @modelcontextprotocol/server-filesystem C:\Users\username\Desktop, to see errors without Claude in the way.

Security basics

A local server runs with your Windows account's permissions. The MCP guide warns that the Filesystem server "can perform any file operations you can perform manually" in the folders you list. Give it the narrowest folders you can, and approve each tool call yourself. Our MCP security risks guide covers what else to check before installing a server.

Next step

If several people on your team need the same servers, Team and Enterprise Owners can upload custom extensions for one-click install. For help choosing and rolling out servers, see our MCP development service, or compare clients in best MCP clients.

Frequently asked questions