In this module, we install Claude Code, sign in with our plan, and make our first change to Repair Desk. Module 1 works in the module-01 folder you made in lesson 0.3, the copy of source\module-00. Open it in your editor and in a terminal. Module 1 starts there.

Running the Installer

The simplest way is the native installer, a one-line install script from Anthropic. It also keeps Claude Code up to date on its own, so we recommend it.

On Windows, use Windows PowerShell, not the Command Prompt. The macOS and Linux command also works in the Windows Subsystem for Linux (WSL). Run the one for your system:

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

curl -fsSL https://claude.ai/install.sh | bash

The command prints little or nothing while it downloads, sometimes for a minute or more. Nothing is stuck. Wait for the prompt to come back. Then close every terminal window and open a new one, because a terminal only finds a new program when it starts.

If your company installs software through a package manager, you can use that instead. On Windows it is winget:

winget install Anthropic.ClaudeCode
winget upgrade Anthropic.ClaudeCode

On macOS, Homebrew does the same with brew install --cask claude-code and brew upgrade claude-code. There is one difference from the native installer. A winget or Homebrew install does not update itself, so the upgrade line is the one you run every few weeks.

Claude Code does not need git to run.

On Windows it runs its shell commands through PowerShell. With Git for Windows installed, as lesson 0.2 asked, it can use Git Bash too, and one session may use both. The course shows both.

Checking the Installation

Two commands tell us the install worked. They are the same on every system. Run them in the new terminal:

claude --version
claude doctor

The first one answers with the version:

2.1.277 (Claude Code)

Yours will most likely be newer, and that is fine.

The second one, claude doctor, checks the installation and the settings files and prints what it found, without starting a session.

When something is wrong, it also says how to fix it. This is what it printed on our machine. We removed the install path and the commit hash, because they only describe our computer:

Claude Code doctor

Running: npm-global (2.1.277)
Platform: win32-x64
Config install method: global
Search: OK (bundled)
Auto-updates: disabled (set by env: DISABLE_AUTOUPDATER)
Auto-update channel: latest

No installation issues found.

The two lines worth reading are the first and the auto-updates line. The first tells you which install answered. Ours says npm-global because we installed Claude Code another way, with npm. After the native installer, yours says native.

The second tells you whether it updates itself. On our machine it does not, because we turned updates off while writing the course. On yours, it should say enabled.

That is everything you install. Claude Code is one program that sends commands to your shell. The editor extensions and the desktop app are optional, and this course needs neither.

Windows Install Problems

Three problems come up on Windows again and again. Each one stops the install or the claude command from working, and each has a short fix.

The first is a claude that PowerShell cannot find, even in a new window. The installer did not add its folder to your executable search path (PATH), the list of folders Windows searches for a command. Check whether the folder is there:

$env:PATH -split ';' | Select-String '\.local\\bin'

If that prints nothing, add the folder, then close every terminal window and open a new one once more:

$currentPath = [Environment]::GetEnvironmentVariable('PATH', 'User')
[Environment]::SetEnvironmentVariable('PATH', "$currentPath;$env:USERPROFILE\.local\bin", 'User')

Until then, the program is at %USERPROFILE%\.local\bin\claude.exe, and you can run it from there at any time with & "$env:USERPROFILE\.local\bin\claude.exe" --version.

The second is the 32-bit PowerShell. The Start menu has two PowerShell entries, and the one marked x86 runs a 32-bit shell. Claude Code refuses to install there with the message Claude Code does not support 32-bit Windows. Use the plain Windows PowerShell entry instead.

The third is an older copy of Claude Desktop. It registers its own claude command on the PATH. If it sits earlier on the PATH than the new install, claude --version answers with the old one.

The fix is to update Claude Desktop, or remove it. Lesson 10.1 shows how to find which copy answers.

Fixing Setup With Claude Code

Once Claude Code starts at all, even by its full path, it can fix the rest of its own setup. It runs commands in your shell, so it can read your PATH, find the old copy of a program and change a user setting, on Windows, macOS and Linux alike.

Start it, finish the sign-in from lesson 1.3, and describe the problem in plain words, for example: “claude only starts by its full path. Find out why and add its folder to my user PATH.”

Then read the commands it ran before you close the session. The manual steps above stay the fallback for the case where it does not start at all.

In the next lesson, we sign in with our plan.