byrobxAI.

Install Claude Code

You will install Claude Code on Mac or Windows, log in, and ask your first question about a folder on your computer.

Beginner. 10 min read. Updated 25 October 2026.

This guide takes you from nothing to your first answer from Claude Code. You need about ten minutes and a paid Claude plan.

What a terminal is

A terminal is a window where you type commands instead of clicking. You type one line, press Enter, and the computer does it. On a Mac the app is called Terminal. On Windows it is called PowerShell. It looks old, but you only need four or five commands, and I give you every one of them below.

Prefer to skip the terminal completely? Read No terminal: the desktop app first.

Before you start

  • A paid Claude plan. Claude Code needs Pro, Max, Team or Enterprise, or a Claude Console account. The free plan does not include Claude Code.
  • A recent computer. macOS 13 or newer, or Windows 10 (version 1809) or newer. 4 GB of memory is enough.
  • An internet connection.

Install on a Mac

  1. Open Terminal. Press Cmd + Space, type Terminal, press Enter. A window with a blinking cursor opens.
  2. Copy this line, paste it with Cmd + V, and press Enter:
curl -fsSL https://claude.ai/install.sh | bash
  1. Wait. The command shows no progress while it downloads. When it is done you see a message that Claude Code is installed.
  2. Close the window and open a new Terminal window. Then check the install:
claude --version

You see a version number followed by (Claude Code). That means it works.

Check: using Homebrew already? brew install --cask claude-code works too. Homebrew does not update Claude Code by itself, so run brew upgrade claude-code now and then.

Install on Windows

  1. Open PowerShell. Press Win + X and choose Windows PowerShell or Terminal.
  2. Check that you are in PowerShell. Each line starts with PS C:\Users\YourName>. If you see C:\Users\YourName> without PS, you are in CMD, which uses different commands.
  3. Copy this line, paste it with Ctrl + V, and press Enter:
irm https://claude.ai/install.ps1 | iex
  1. Wait until the installer says Claude Code is installed. It shows no progress while it downloads.
  2. Close PowerShell, open a new window, and check:
claude --version

Check: Anthropic recommends Git for Windows on Windows. It is optional. Without it, Claude Code uses PowerShell to run commands. With it, Claude Code can also use Bash. You don’t need to learn Git. Click Next on every screen of the installer and keep the defaults.

The native install on Mac and Windows updates itself in the background. You don’t need to do anything.

Make a project folder

Claude Code always works inside one folder. That folder is your project. Everything Claude reads and writes stays there.

Make one for your AI company. On a Mac:

mkdir ~/my-ai-company
cd ~/my-ai-company

On Windows, in PowerShell:

mkdir $HOME\my-ai-company
cd $HOME\my-ai-company

mkdir makes the folder. cd moves you into it. Your terminal now “stands” in that folder, and any program you start there works on it.

Common mistake: a folder name with spaces. It works, but you then need quotes around the path every time. Use dashes: my-ai-company.

Put a file in it so Claude has something to read. Any text works: your About page, a few notes on your offer, a post you wrote. Save it as notes.md or notes.txt in the folder.

Start Claude Code and log in

In the same window, still inside your folder, type:

claude

The first time, Claude Code asks you to log in. A browser window opens. Sign in with your Claude account and approve. Then go back to the terminal.

You only log in once. Claude Code saves your login.

Now you see the Claude Code prompt. Above it you see the version, the model and the folder you are in. Check that the folder is my-ai-company.

Ask your first question

Type a question in plain English and press Enter:

what is in this folder?

Claude reads your files and answers. Try a second one about your own text:

read notes.md and tell me in three lines what this business sells and to whom

That is the whole loop. You ask, Claude reads the files in your folder, Claude answers or writes.

A few things to know:

  • Claude asks before it changes a file. Press Enter on Yes to approve, or choose No.
  • Press Esc to stop Claude while it works.
  • Type /help to see the commands.
  • Type /exit, or press Ctrl + D twice, to leave Claude Code.

Next time, open the terminal, cd into your folder, and type claude again.

No terminal: the desktop app

The Claude desktop app has Claude Code built in. You don’t need to install anything else.

  1. Download the Claude app for Mac or Windows from claude.com/download and sign in.
  2. Click the Code tab at the top of the sidebar.
  3. Under the prompt box, choose the Local environment, then Open folder… and pick your my-ai-company folder.
  4. Type your question, the same way as above.

The desktop app also needs a Pro, Max, Team or Enterprise plan. If it asks you to upgrade when you click Code, your plan doesn’t include Claude Code.

The guides on this site show terminal commands. In the desktop app you type the same questions and the same slash commands in the prompt box.

When it doesn’t work

“command not found: claude” or “‘claude’ is not recognized”

The install worked, but your terminal can’t find the program yet.

  1. Close the terminal and open a new window. Try claude --version again. Old windows don’t see the change.
  2. Still not found on a Mac? Add the install folder to your path with these two lines, then open a new window:
echo 'export PATH="$HOME/.local/bin:$PATH"' >> ~/.zshrc
source ~/.zshrc
  1. Still not found on Windows? Run these two lines in PowerShell, then close it and open a new window:
$currentPath = [Environment]::GetEnvironmentVariable('PATH', 'User')
[Environment]::SetEnvironmentVariable('PATH', "$currentPath;$env:USERPROFILE\.local\bin", 'User')

The installer also prints the exact fix for your computer at the end, under “Setup notes”. Read it.

“irm is not recognized” on Windows

You are in CMD, not PowerShell. Close the window and open PowerShell with Win + X.

Claude talks about the wrong files

You started Claude Code in the wrong folder. Type /exit, then cd into your project folder and start claude again. The folder name shows above the prompt when Claude Code starts.

Login fails, or you get a 403 error

  • Check that your plan is Pro, Max, Team or Enterprise. The free plan does not work.
  • Check that your subscription is active at claude.ai/settings.
  • Reset your login: type /logout, close Claude Code, start claude again and log in.
  • No browser opens? Press c in the terminal to copy the login link and paste it in your browser.

Something else

Run this in your terminal (not inside Claude Code). It checks your install and tells you what is wrong:

claude doctor

For every other error, the official troubleshooting page lists the message and the fix.

Glossary

Word What it means
Terminal A window where you type commands. Terminal on Mac, PowerShell on Windows.
Folder (directory) A place on your computer that holds files. Developers say directory. Same thing.
Project The one folder Claude Code works in. Your business knowledge and your employees live there.
Command One line you type in the terminal and run with Enter, like cd or claude.
Slash command A command you type inside Claude Code, starting with /, like /help or /exit. Each skill you install also gets one.

Next

Give Claude Code something to know about your business: Write your business down once.