Running Windows in Raspberry Pi: ARM64 IoT & GPIO Guide

If you want to run windows in raspberry pi hardware for a desktop experience, the latest boards are great. But if your goal is native hardware control—toggling GPIO pins, reading I2C sensors, or driving PWM motors—chasing the newest silicon will brick your project. Microsoft killed Windows 10 IoT Core, and the community-driven Windows on Raspberry (WoR) project is the only viable path for Windows 11 ARM64. However, the Raspberry Pi 5’s custom RP1 southbridge chip currently lacks mature Windows Board Support Package (BSP) drivers for GPIO.

The direct answer for embedded engineers: You must use the Raspberry Pi 4 Model B (8GB) for reliable native Windows GPIO control. Below is the exact decision framework, hardware list, and C# .NET 8 code to get your Windows IoT build running without the usual boot-loop headaches.

The Decision Path: Pi 4 vs Pi 5 for Windows IoT

Before ordering parts, you need to select the right board variant. Do not default to the newest model. Use this decision matrix to finalize your hardware pick.

Parts List & Hardware Spec Sheet

Standard microSD cards will die within months running Windows due to constant pagefile and telemetry writes. You need high-endurance storage and robust thermal management.

• Compute: Raspberry Pi 4 Model B (8GB RAM) - ~$75
• Storage: SanDisk Max Endurance 128GB microSD (U3, V30) - ~$22 (Rated for 120,000 hours of continuous recording/rewriting)
• Power: Official Raspberry Pi 27W USB-C PD Power Supply (White) - ~$12 (Must be official to prevent brownout throttling)
• Enclosure/Cooling: Argon ONE V3 Aluminum Case with active fan - ~$25 (Provides full-size HDMI ports and NVMe/USB routing)
• Peripherals: Logitech K400 Plus Wireless Touch Keyboard - ~$30 (For initial OOBE setup)

Flashing Windows 11 ARM64 via WoR

Microsoft does not provide a direct Windows 11 ARM64 ISO for the Pi. We use the Windows on Raspberry (WoR) flasher to fetch Unified Update Platform (UUP) dumps and inject the necessary Pi 4 BSP drivers.

1. Download WoR-Flasher: Clone or download the latest release from the WoR project GitHub repository on your main Windows PC.
2. Configure the Image: Run wor-flasher.sh (via WSL2 or native Linux). Select Windows 11 ARM64 and choose the Raspberry Pi 4 target.
3. Inject BSP Drivers: The script will automatically pull the WoR BSP driver pack (ensure it is v1.3.0 or newer for BCM2711 GPIO stability). It patches the UEFI firmware and injects the ACPI tables.
4. Flash and Boot: Write the image to your SanDisk Max Endurance card. Insert it into the Pi 4, connect power, and wait 15-20 minutes for the first-boot OOBE (Out of Box Experience) file expansion.

Native GPIO Control: C# .NET 8 Code

While Python is common on Linux-based Pi OS, Windows on Raspberry requires native ARM64 binaries for reliable hardware access. We use C# with the System.Device.Gpio library, which maps directly to the Windows IoT BSP drivers.

Pin Mapping Table

Compilable C# .NET 8 Application

Create a new .NET 8 Console App targeting win-arm64. Add the NuGet package System.Device.Gpio.

using System;
using System.Device.Gpio;
using System.Threading;

namespace WindowsPiGPIO
{
    class Program
    {
        // BCM Pin Definitions
        const int LedPin = 17;
        const int ButtonPin = 27;

        static void Main(string[] args)
        {
            Console.WriteLine("Initializing Windows ARM64 GPIO Controller...");

            try
            {
                // LogicalBoard = BCM numbering scheme
                using GpioController controller = new GpioController(PinNumberingScheme.LogicalBoard);
                
                controller.OpenPin(LedPin, PinMode.Output);
                controller.OpenPin(ButtonPin, PinMode.InputPullUp);

                Console.WriteLine("Press the button to toggle the LED. Ctrl+C to exit.");

                bool ledState = false;

                while (true)
                {
                    // Read button (ActiveLow because of PullUp)
                    if (controller.Read(ButtonPin) == PinValue.Low)
                    {
                        ledState = !ledState;
                        controller.Write(LedPin, ledState ? PinValue.High : PinValue.Low);
                        Console.WriteLine($"Button pressed. LED State: {ledState}");
                        
                        // Simple debounce delay
                        Thread.Sleep(250); 
                    }
                    Thread.Sleep(50);
                }
            }
            catch (PlatformNotSupportedException ex)
            {
                Console.WriteLine($"FATAL: {ex.Message}");
                Console.WriteLine("Ensure you are running the ARM64 native build, not x86 emulation.");
            }
            catch (Exception ex)
            {
                Console.WriteLine($"Hardware Error: {ex.Message}");
            }
        }
    }
}

Build command: dotnet publish -c Release -r win-arm64 --self-contained. Transfer the published folder to the Pi via SMB and run the .exe natively.

Debugging Boot and GPIO Failures

When running windows in raspberry pi environments, the BSP layer between the Windows kernel and the BCM2711 silicon is where things break. If your code crashes or the board fails to boot, follow this diagnostic path.

The Exact Error String

If your C# app immediately crashes upon instantiation, you will see this exact exception:

System.PlatformNotSupportedException: 'GPIO is not supported on this platform.'

Ranked Causes & Fixes

1. Running x86 Emulation (Most Likely): You compiled your .NET app for win-x86 or win-x64 and are running it through Windows 11's built-in x86 emulator. The emulator cannot pass hardware interrupts to the GPIO controller. Fix: Recompile strictly for win-arm64.
2. Missing or Corrupt WoR BSP: The WoR flasher failed to inject the bcm2836.inf GPIO driver package during image creation. Fix: Open Device Manager, check under "System Devices" for "BCM283x GPIO Controller". If missing, re-flash the SD card with the latest WoR-flasher script.
3. Pin Numbering Scheme Mismatch: You used physical pin numbers (e.g., 11) while the controller was set to PinNumberingScheme.LogicalBoard (BCM 17). Fix: Align your code constants with the scheme defined in the constructor.

First Three Things to Check When It Fails

• 1. Verify Power Delivery: Use a multimeter to check the 5V and GND pins on the GPIO header. If you read below 4.85V under load, the Pi is brownout-throttling, which disables peripheral clocks. Upgrade your USB-C cable and power brick.
• 2. Check Device Manager: Open Windows Device Manager and look for yellow warning triangles under "System Devices". A missing ACPI BIOS ERROR in the Event Viewer usually points to an outdated UEFI firmware partition on the SD card.
• 3. Validate the .NET Runtime: Open PowerShell on the Pi and run dotnet --info. Ensure the Runtime Environment shows OS Architecture: Arm64. If it shows X64, you installed the wrong .NET SDK.

Extending and Simplifying the Build

Once you have stable GPIO toggling, you will inevitably want to add environmental sensors or displays. Here is how to scale the project without breaking the Windows BSP.

How to Simplify: The ESP32 I/O Expander Route

If you find Windows 11 background tasks causing micro-stutters in your PWM motor control or high-speed sensor polling, offload the real-time I/O to an ESP32-C3. Connect the ESP32 to the Pi 4 via USB-UART. The Pi runs the heavy Windows UI and database logging, while the ESP32 handles microsecond-precise GPIO toggling via simple serial commands. This completely bypasses the Windows GPIO latency issue.

How to Extend: Adding an I2C BME280 Sensor

To add temperature and humidity logging, wire a Bosch BME280 breakout board to the Pi's I2C1 bus (BCM 2 / SDA, BCM 3 / SCL). You will need to enable the I2C bus in the WoR configuration utility (found in the Windows Start Menu under "Raspberry Pi Configuration"). Once enabled, use the System.Device.I2c NuGet package alongside the Iot.Device.Bmxx80 library to read the sensor data natively in C#. This keeps your entire stack in compiled ARM64 code, ensuring maximum performance on the Pi 4's Cortex-A72 cores.

For deeper hardware specifications and ACPI table mappings, always refer to the official Raspberry Pi compute documentation and the WoR project release notes before attempting custom kernel driver injections.