How to fix error during connect: This error may indicate that the docker daemon is not running. in Docker

The most common solution is simply launching Docker Desktop:

1. Click the Windows Start menu
2. Type "Docker Desktop" and click the application
3. Wait for the whale icon to appear in the system tray
4. The icon animates while starting - wait until it becomes solid

Using PowerShell:

Start-Process "C:\Program Files\Docker\Docker\Docker Desktop.exe"

Tip: Enable "Start Docker Desktop when you sign in to Windows" in Docker Desktop Settings to avoid this issue in the future.

Once Docker Desktop shows as running, verify the daemon is accessible:

docker version

You should see both Client and Server sections. If only Client appears, the daemon is still not running.

Check detailed status:

docker info

This should display information about containers, images, storage driver, and more.

Docker may require elevated privileges to connect:

1. Close your current terminal
2. Right-click on PowerShell or Command Prompt
3. Select "Run as administrator"
4. Try your Docker command again

Alternative - Add yourself to docker-users group:

# Run in elevated PowerShell
net localgroup docker-users "$env:USERNAME" /ADD

Log out and log back in for the group change to take effect.

If Docker Desktop appears running but commands fail, restart the service:

Using Windows Services:
1. Press Win+R, type services.msc, press Enter
2. Find "Docker Desktop Service"
3. Right-click and select "Restart"

Using PowerShell (Administrator):

Restart-Service -Name "com.docker.service"

Using the System Tray:
1. Right-click the Docker whale icon
2. Click "Restart"

If you've previously used Windows containers, Docker might be in the wrong mode:

& "C:\Program Files\Docker\Docker\DockerCli.exe" -SwitchDaemon

Or right-click the Docker whale icon and select "Switch to Linux containers" (or vice versa).

Note: Most users should use Linux containers (the default).

If using the WSL2 backend (default on Windows 10/11 Home):

# Update WSL
wsl --update

# Shut down all WSL instances
wsl --shutdown

Then restart Docker Desktop.

Check WSL distributions:

wsl -l -v

You should see "docker-desktop" and "docker-desktop-data" in the list.

Docker requires virtualization support. Verify it's enabled:

Check virtualization status:
1. Open Task Manager (Ctrl+Shift+Esc)
2. Go to the Performance tab
3. Look for "Virtualization: Enabled"

Enable Windows features:
1. Open "Turn Windows features on or off"
2. Enable these features:
- Hyper-V (for Windows Pro/Enterprise)
- Virtual Machine Platform
- Windows Subsystem for Linux
- Windows Hypervisor Platform
3. Click OK and restart Windows

If virtualization shows as Disabled, you need to enable it in BIOS/UEFI:
1. Restart your computer
2. Enter BIOS setup (usually F2, F12, Del, or Esc during boot)
3. Find "Intel VT-x", "AMD-V", or "Virtualization Technology"
4. Enable it and save/exit

If other solutions don't work, try resetting Docker:

1. Open Docker Desktop
2. Click the gear icon (Settings)
3. Go to "Troubleshoot" section
4. Click "Reset to factory defaults"

Warning: This removes all containers, images, volumes, and settings. Export important images first:

docker save my-image:tag -o my-image-backup.tar

As a last resort, perform a complete reinstall:

1. Uninstall Docker Desktop:
- Open Windows Settings > Apps
- Find Docker Desktop and uninstall

2. Remove leftover data:

Remove-Item -Recurse -Force "$env:APPDATA\Docker" -ErrorAction SilentlyContinue
Remove-Item -Recurse -Force "$env:LOCALAPPDATA\Docker" -ErrorAction SilentlyContinue
Remove-Item -Recurse -Force "$env:PROGRAMDATA\Docker" -ErrorAction SilentlyContinue
Remove-Item -Recurse -Force "$env:PROGRAMDATA\DockerDesktop" -ErrorAction SilentlyContinue

3. Unregister WSL distributions:

wsl --unregister docker-desktop
wsl --unregister docker-desktop-data

4. Restart Windows

5. Download and install the latest Docker Desktop from https://www.docker.com/products/docker-desktop/