Your terminal is not a mystery

The terminal is a window that runs one program and shows you its output. That is genuinely all it is. What makes it feel like a mystery is that it has no visible controls, so everything you might want to do is a key combination you were never told.

There are about six of them. Learn those six and the window stops being a mystery, which matters, because in module 4 you will be running four Claude sessions inside one of these windows at the same time.

Panes, and the word that trips everyone

A tab is a whole separate terminal. A pane is a slice of the current one, side by side with the others. Four Claude sessions in four panes means you can see all four at once, which is the entire point of module 4.

Here is the trap, and it is worth reading twice. In Windows Terminal, splitting "vertically" puts the new pane to the right, not below. The word describes the line drawn between the panes, not the direction they stack. Microsoft says so plainly, and it is the opposite of what almost everyone expects.

It gets worse if you have used tmux, where the naming is inverted: tmux's "horizontal" split is the one that puts panes side by side. If you know tmux, you have to unlearn it here. These two facts cause more wrongly built layouts than anything else in this course.

Try it now, because muscle memory is the only way this sticks. Split your window in two, put a Claude session in one side and leave the other on a plain shell prompt, then move between them without touching the mouse.

Four ways it goes wrong on Windows

Four failures cover almost everything, and all four are on Windows. The first two stop it starting; the second two happen inside a session that is already running. Run through them in order.

"'claude' is not recognized" — nine times out of ten you are in the terminal window that was open when you installed. Close it. Open a new one. If a fresh window still fails, your PATH did not pick up the install location, and the next command will tell you.

claude doctor

A check of your installation: where the binary is, what version, and what is wrong with it. This is the first thing to run before searching for an error message.

It starts but the Bash tool fails. Claude Code uses Git Bash for shell commands on Windows when Git for Windows is installed, and PowerShell when it is not. If Git is installed somewhere unusual it will not be found. Point at it directly in your settings file:

{
  "env": {
    "CLAUDE_CODE_GIT_BASH_PATH": "C:\\Program Files\\Git\\bin\\bash.exe"
  }
}

Backspace deletes a whole word. A known Windows quirk: some terminals send Backspace in a form Claude Code reads as Ctrl+Backspace. Set CLAUDE_CODE_BS_AS_CTRL_BACKSPACE=0 in your environment and it behaves.

Pasting an image does nothing. On Windows and WSL the shortcut is Alt+V, not Ctrl+V. Many terminals swallow Ctrl+V before Claude Code ever sees it.

While you are here, two Windows keys worth writing down because they come up constantly later: Shift+Tab cycles permission modes, and if that does nothing in your terminal, Alt+M does the same job. Ctrl+Backspace deletes the previous word.