How to fix image operating system "linux" cannot be used on this platform in Docker

First, verify which container mode Docker is currently using:

Via System Tray:
1. Look for the Docker whale icon in the Windows system tray (bottom-right)
2. Right-click the Docker icon
3. Look at the menu - it will show either "Switch to Windows containers..." or "Switch to Linux containers..."
4. If you see "Switch to Linux containers...", Docker is currently in Windows mode

Via Command Line:

docker version

Look at the "OS/Arch" line under the Server section:
- linux/amd64 means Linux containers mode
- windows/amd64 means Windows containers mode

You can also check:

docker info | findstr "OSType"

The quickest way to switch container modes is through the Docker Desktop system tray:

1. Find the Docker whale icon in your Windows system tray (bottom-right corner)
2. Right-click on the Docker icon
3. Click "Switch to Linux containers..."
4. Docker will prompt you to confirm - click "Switch"
5. Wait for Docker to restart (this may take a minute)

After switching, verify the change:

docker version

The Server "OS/Arch" should now show linux/amd64.

Note: If you don't see the "Switch to Linux containers..." option:
- Docker is already in Linux mode (and the issue might be elsewhere)
- Docker Desktop may need to be restarted
- Check if WSL 2 is properly installed (required for Linux containers on Windows Home)

If you're on Windows 10/11 Home or want the recommended Docker configuration, ensure WSL 2 is enabled:

Install WSL 2:

# Enable WSL feature
wsl --install

# Or manually enable required features
dism.exe /online /enable-feature /featurename:Microsoft-Windows-Subsystem-Linux /all /norestart
dism.exe /online /enable-feature /featurename:VirtualMachinePlatform /all /norestart

# Set WSL 2 as default
wsl --set-default-version 2

Configure Docker Desktop to use WSL 2:
1. Open Docker Desktop
2. Go to Settings (gear icon)
3. Select General
4. Ensure "Use the WSL 2 based engine" is checked
5. Click Apply & Restart

After Docker restarts, it should be in Linux containers mode.

Sometimes Docker gets stuck in an inconsistent state. Toggling between modes can fix this:

1. Right-click the Docker icon in the system tray
2. Click "Switch to Windows containers..." (even if you want Linux)
3. Wait for Docker to restart
4. Right-click the Docker icon again
5. Click "Switch to Linux containers..."
6. Wait for Docker to restart

This toggle resets Docker's container runtime state and can resolve issues where Docker reports the wrong mode.

Verify the fix:

docker pull hello-world
docker run hello-world

If this works, Docker is properly configured for Linux containers.

Linux containers on Windows require virtualization support:

Check Windows version:

winver

- Windows 10/11 Home: Requires WSL 2 backend only (no Hyper-V)
- Windows 10/11 Pro/Enterprise: Can use either WSL 2 or Hyper-V backend

Enable Hyper-V (Pro/Enterprise only):

# Using PowerShell as Administrator
Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All

Or via Windows Features:
1. Press Win + R, type optionalfeatures, press Enter
2. Check Hyper-V and all sub-items
3. Click OK and restart

For Windows Home users:
WSL 2 is your only option for Linux containers. Make sure it's properly installed as described in the previous step.

If you're running Windows in a virtual machine (VMware, VirtualBox, Azure, AWS), nested virtualization must be enabled:

For VMware:
1. Edit the VM settings
2. Go to Processors
3. Enable "Virtualize Intel VT-x/EPT or AMD-V/RVI"

For Hyper-V nested VMs:

# Run on the Hyper-V host
Set-VMProcessor -VMName <YourVMName> -ExposeVirtualizationExtensions $true

For Cloud VMs (Azure/AWS):
- Azure: Use VM sizes that support nested virtualization (Dv3, Ev3, etc.)
- AWS: Use .metal instance types or Nitro-based instances

If nested virtualization isn't available:
Consider using Docker on a Linux VM directly, or use a remote Docker host.

If the issue persists, perform a complete restart of Docker Desktop:

Method 1: Via System Tray
1. Right-click the Docker icon
2. Click "Quit Docker Desktop"
3. Wait 30 seconds
4. Start Docker Desktop from the Start menu

Method 2: Via Task Manager

# Stop all Docker processes
Stop-Process -Name "Docker Desktop" -Force -ErrorAction SilentlyContinue
Stop-Process -Name "com.docker.backend" -Force -ErrorAction SilentlyContinue
Stop-Process -Name "com.docker.proxy" -Force -ErrorAction SilentlyContinue

# Wait a moment
Start-Sleep -Seconds 5

# Start Docker Desktop
Start-Process "$env:ProgramFiles\Docker\Docker\Docker Desktop.exe"

Method 3: Restart Docker service

Restart-Service com.docker.service

After restart, verify Linux mode:

docker info | findstr "OSType"

As a last resort, reset Docker Desktop to its default configuration:

Via Docker Desktop UI:
1. Open Docker Desktop
2. Click the gear icon (Settings)
3. Go to Troubleshoot (or Reset tab)
4. Click "Reset to factory defaults"
5. Confirm the reset

Manual reset (if UI is not accessible):

# Stop Docker
Stop-Process -Name "Docker Desktop" -Force -ErrorAction SilentlyContinue

# Remove Docker settings (keeps images)
Remove-Item "$env:APPDATA\Docker\settings.json" -ErrorAction SilentlyContinue

# For complete reset, also remove:
Remove-Item -Recurse -Force "$env:APPDATA\Docker" -ErrorAction SilentlyContinue
Remove-Item -Recurse -Force "$env:LOCALAPPDATA\Docker" -ErrorAction SilentlyContinue

# Restart Docker Desktop
Start-Process "$env:ProgramFiles\Docker\Docker\Docker Desktop.exe"

After reset, Docker should default to Linux containers mode (if WSL 2/Hyper-V is available).