Windows Setup Guide All Tiers

This guide walks you through every step of setting up a complete development environment on Windows, from installing Git to running your first PairCoder project. It assumes you have never used a command-line tool, Git, or Python before.

Step 0: Prerequisites Checklist

Before we begin, make sure you have:

• Windows 10 or Windows 11 — older versions won't work with Claude Code.
• At least 10 GB of free disk space — to check, open Settings → System → Storage. Your main drive (usually "C:") should show at least 10 GB available.
• An internet connection — you'll be downloading several tools.
• A GitHub account — if you don't have one, sign up free at github.com/signup.
• An Anthropic account — sign up at claude.ai. You'll need a Claude subscription (Pro or Max) or an API key.

Step 1: Install Git for Windows

Git is a tool that tracks changes to your code, like a "save history" for your project. Claude Code also depends on Git internally, so this must be installed first.

Download and install

1. Go to git-scm.com/downloads/win and download the installer.
2. Run the installer. Most defaults are fine, but watch for one critical screen:

3. Finish the installer with the remaining defaults.

Already installed Git without adding to PATH?

If you installed Git previously and the git command doesn't work in PowerShell, you need to add it to PATH manually. Here's how:

1. Find where Git is installed. Right-click the "Git Bash" icon on your desktop or Start menu, click Properties, and look at the Target field. Or, open Git Bash and type:
   bash Copy

   cd / && pwd -W

   Common locations: C:\Program Files\Git\ or C:\Users\YourName\AppData\Local\Programs\Git\
2. Press the Windows key, type "environment variables", and click "Edit the system environment variables".
3. Click "Environment Variables..." at the bottom.
4. Under "User variables", find Path and click Edit.
5. Click New and add the path to Git's cmd folder. For example: C:\Program Files\Git\cmd
6. Click OK on all dialogs to save.
7. Close and reopen any PowerShell or terminal windows for the change to take effect.

Verify Git is working by opening PowerShell and typing:

git --version
# Should show something like: git version 2.47.1.windows.1

Step 2: Configure Git Bash for Claude Code

Claude Code uses a program called "Git Bash" (which was installed along with Git) as its shell on Windows. You need to tell Claude Code where to find Git Bash by setting an environment variable — think of it as a sticky note that tells your computer where a program lives.

Set the environment variable permanently

1. Press the Windows key, type "environment variables", and click "Edit the system environment variables".
2. Click "Environment Variables..." at the bottom.
3. Under "User variables", click New.
4. Set the variable name to: CLAUDE_CODE_GIT_BASH_PATH
5. Set the variable value to the path of bash.exe inside your Git installation. The most common path is:
   text Copy

   C:\Program Files\Git\bin\bash.exe

6. Click OK on all dialogs to save.
7. Close and reopen all PowerShell and terminal windows.

$env:CLAUDE_CODE_GIT_BASH_PATH = "C:\Program Files\Git\bin\bash.exe"

Not sure where your bash.exe is? Open PowerShell and run:

Get-Command bash.exe | Select-Object -ExpandProperty Source
# Should show something like: C:\Program Files\Git\bin\bash.exe

Step 3: Install Claude Code

Claude Code is the AI assistant that PairCoder pairs you with. It reads your project files, understands your codebase, and helps you write code.

Run the installer

Paste this command into PowerShell and press Enter:

irm https://claude.ai/install.ps1 | iex

This downloads and runs the official Claude Code installer. It does not require Node.js or npm.

Add Claude Code to PATH

After installation, the claude command lives in %USERPROFILE%\.local\bin. If claude --version doesn't work after installation, add this folder to your PATH:

1. Press the Windows key, type "environment variables", and click "Edit the system environment variables".
2. Click "Environment Variables..." → Under "User variables", find Path → click Edit.
3. Click New and add: %USERPROFILE%\.local\bin
4. Click OK on all dialogs.

Verify the installation

Open a fresh PowerShell window and run:

claude --version

You should see a version number. If you get an error, see the troubleshooting section below.

Step 4: Install Python

Python is the programming language that PairCoder is built with. You need it installed to run PairCoder commands.

1. Go to python.org/downloads and download Python 3.12 or newer.
2. Run the installer.

3. Click "Install Now" (the default recommended option is fine).
4. When installation finishes, close and reopen PowerShell.

Verify Python is installed

python --version
# Should show: Python 3.12.x (or newer)

pip --version
# Should show: pip 24.x from ...

Step 5: Install VS Code

VS Code (Visual Studio Code) is a free code editor made by Microsoft. It's where you'll write code and interact with Claude Code through an integrated terminal.

1. Download from code.visualstudio.com and run the installer.
2. During installation, check "Add to PATH" when prompted.
3. Open VS Code after installation.

Install recommended extensions

Extensions add extra features to VS Code. Install these by clicking the square icon in the left sidebar (or pressing Ctrl+Shift+X), then searching for each name:

• Python (by Microsoft) — required for Python development
• GitLens (optional) — adds helpful Git information to your editor

Set up the Python interpreter

Tell VS Code which Python installation to use:

1. Press Ctrl+Shift+P to open the Command Palette.
2. Type "Python: Select Interpreter" and click it.
3. Choose the Python version you just installed (e.g., "Python 3.12.x").

Step 6: Set Up a GitHub SSH Key

SSH keys let your computer prove its identity to GitHub without you typing your password every time. Think of it like a digital keycard — your computer shows it to GitHub, and GitHub lets you in.

Generate a key

Open PowerShell and run this command (replace with your actual email):

ssh-keygen -t ed25519 -C "your-email@example.com"

When it asks where to save the file, press Enter to accept the default location. When it asks for a passphrase, you can press Enter twice to skip it (or set one for extra security).

Start the SSH agent and add your key

# Start the SSH agent service
Get-Service ssh-agent | Set-Service -StartupType Automatic
Start-Service ssh-agent

# Add your key to the agent
ssh-add "$env:USERPROFILE\.ssh\id_ed25519"

Copy the public key

Get-Content "$env:USERPROFILE\.ssh\id_ed25519.pub" | Set-Clipboard

This copies your public key to your clipboard. (The public key is safe to share — it's like your lock, not your key.)

Add the key to GitHub

1. Go to github.com/settings/keys (you may need to log in).
2. Click "New SSH Key".
3. Give it a title (e.g., "My Windows PC").
4. Paste the key from your clipboard into the "Key" field.
5. Click "Add SSH Key".

Test the connection

ssh -T git@github.com

If it asks about "authenticity of the host," type yes and press Enter. You should see: Hi username! You've successfully authenticated

Step 7: Create a Project Repository

A repository (or "repo") is a project folder tracked by Git. Let's create one on GitHub and download it to your computer.

Create a repo on GitHub

1. Go to github.com/new.
2. Give your repo a name (e.g., "my-first-project").
3. Check "Add a README file".
4. Click "Create repository".

Clone it to your computer

"Cloning" downloads the repo to your machine so you can work on it locally.

Option A: From VS Code

1. Open VS Code.
2. Press Ctrl+Shift+P and type "Git: Clone".
3. On GitHub, click the green "Code" button, then the "SSH" tab, and copy the URL (looks like git@github.com:username/my-first-project.git).
4. Paste the URL into VS Code and choose a folder to save it in.

Option B: From PowerShell

# Navigate to where you want to keep projects
cd $env:USERPROFILE\Documents

# Clone the repo (replace with your actual URL)
git clone git@github.com:username/my-first-project.git

# Open it in VS Code
code my-first-project

Step 8: Install PairCoder

With Python installed, you can now install PairCoder using pip (Python's package manager — it downloads and installs Python tools).

Install via pip

Open a terminal in VS Code (Ctrl+`) or use PowerShell:

pip install bpsai-pair

Run the setup wizard

Navigate to your project folder (or open VS Code's integrated terminal there) and run the setup wizard:

cd $env:USERPROFILE\Documents\my-first-project
bpsai-pair wizard

The wizard walks you through project setup interactively. Quick Setup works without an API key — choose it if you just want to get started.

Verify PairCoder is working

bpsai-pair --version
# Should show 2.20.0

bpsai-pair status
# Should show your project info

Step 9: Authenticate Claude Code

The last step is to log in to Claude Code so it can access the AI model.

Start Claude Code

In VS Code's terminal or PowerShell, type:

claude

This opens Claude Code. The first time you run it, it will ask you to authenticate. Follow the browser-based flow — it will open a web page where you can log in with your Anthropic account.

Choose your plan

• Claude Pro ($20/month) — includes Claude Code access with generous usage limits. Best starting point for most users.
• Claude Max ($100/month) — much higher usage limits for power users who spend all day coding with Claude.
• API key — pay-per-use billing. Better if you use Claude Code only occasionally or want precise cost control.

Once authenticated, Claude Code is ready to use. You can ask it questions about your project, have it write code, or use PairCoder's workflows.

Common Issues

"command not recognized" or "not found" errors

This almost always means the program isn't in your PATH. PATH is a list of folders where Windows looks for programs when you type a command.

Fix:

1. Make sure you checked "Add to PATH" during installation (Git, Python, or Claude Code).
2. Close and reopen your terminal. Environment variable changes only take effect in new windows.
3. If you missed the PATH checkbox during installation, add the program's folder to PATH manually using the Environment Variables UI (see Step 1 for instructions).

Claude Code installer says "complete" but claude doesn't work

The installer found that Git Bash is missing or not discoverable. It prints a success message regardless, which is misleading.

Fix:

1. Set CLAUDE_CODE_GIT_BASH_PATH as described in Step 2.
2. Close and reopen PowerShell.
3. Re-run the installer: irm https://claude.ai/install.ps1 | iex

Git Bash not found / CLAUDE_CODE_GIT_BASH_PATH issues

If you set the variable but it's not being detected:

• Verify the path is correct — open File Explorer and navigate to the path you entered. You should see bash.exe in that folder.
• Make sure you set it as a User variable, not a System variable (unless you have admin access).
• Check for typos: the variable name must be exactly CLAUDE_CODE_GIT_BASH_PATH.

Disk space error (ENOSPC)

The Claude Code installer needs space to download files. Free up disk space by:

• Open Settings → System → Storage and run "Storage Sense" or "Free up space now".
• Empty the Recycle Bin.
• Uninstall programs you no longer use.

Python not found after installation

If python --version doesn't work even though you just installed Python:

• Did you check "Add python.exe to PATH" during installation? If not, re-run the installer and select Modify to enable it.
• Did you restart your terminal after installation? Open a brand-new PowerShell window and try again.
• Try python3 --version instead.

SSH connection refused

If ssh -T git@github.com gives "Connection refused" or "Permission denied":

• Make sure the SSH agent is running:
  powershell Copy

  Get-Service ssh-agent
  # Status should be "Running"

• Make sure your key is added:
  powershell Copy

  ssh-add -l
  # Should list your key fingerprint

• Make sure you added the public key (the .pub file) to GitHub, not the private key.
• If you're behind a corporate firewall, SSH on port 22 may be blocked. Try:
  powershell Copy

  ssh -T -p 443 git@ssh.github.com

VS Code terminal uses wrong shell

If VS Code's terminal opens Command Prompt (CMD) instead of PowerShell:

1. Press Ctrl+Shift+P in VS Code.
2. Type "Terminal: Select Default Profile" and click it.
3. Choose "PowerShell".