Short answer: Docker Desktop is not running (or not finished starting) on your Windows machine. Start it, wait for the engine to report running, then retry your command. ``` failed to connect to the docker api at npipe:////./pipe/dockerdesktoplinuxengine; check if the path is correct and if the daemon is running: open //./pipe/dockerdesktoplinuxengine: the system cannot find the file specified. ``` 1. Open Docker Desktop from the Start menu. Wait until the whale icon in the system tray is steady and the dashboard shows the engine as running. Then run `docker info`. Expected: server details print with no API error. 2. If Desktop is open but the pipe is still missing, check the WSL2 backend: run `wsl -l -v` in PowerShell. `docker-desktop` and `docker-desktop-data` should show Running. If not, run `wsl --start docker-desktop`, then restart Docker Desktop. 3. If Desktop and WSL are both fine, your Windows user may not be in the local `docker-users` group, which the pipe requires. From an admin PowerShell add yourself to that group, restart Docker Desktop, and retry. 4. Still failing: in Docker Desktop go to Settings, Troubleshoot, and Reset to factory defaults. This recreates the pipe. Root cause: on Windows the client reaches the daemon through a named pipe created at Desktop startup. No running Desktop means no pipe, so the client reports it cannot connect. When to use: this exact error on Windows with Docker Desktop. When NOT to use: on Linux or macOS (the daemon listens on a unix socket there, not a named pipe), or when `docker context ls` shows you are pointed at a stale remote context. Variant phrasings: "docker desktop npipe error", "open //./pipe/dockerdesktoplinuxengine the system cannot find the file specified", "docker daemon not running windows". Edge cases: CI runners often hit this because Desktop is still starting when the job runs. Poll `docker info` in a wait loop before the first real command. Also confirm Desktop is in Linux containers mode if your images are Linux.

Context: The Docker CLI talks to the Docker daemon over a Windows named pipe that only exists while Docker Desktop is running. When Desktop is closed, still starting, or its WSL2 backend is down, the pipe is missing and every docker command fails with this connection error. It is not a problem with your images, compose file, or code.