Frequently Asked Questions

Windows on Raspberry imager

Why does the installation process keep failing?

Please check that:

  • you're using the latest version of WoR
  • your SD Card / USB drive are not failing (try with other hardware)
  • your anti-virus solution doesn't interfere with the deployment process (temporarily disable it)

If it fails at the Installing drivers stage, then there's probably an issue with the Windows installation on your PC. In this case, you can try to:

  • reinstall the operating system
  • run the WoR imager in a virtual machine, and passthrough the target drive
  • tell the tool to use a custom version of DISM.

If you want to do the latter, you'll first have to download and install a copy of the Windows ADK, then add the following path: adkInstallPath\Assessment and Deployment Kit\Deployment Tools\ARCH\DISM to the settings.ini file.

Replace adkInstallPath with the path where you've installed the ADK. (it's C:\Program Files (x86)\Windows Kits\10 by default)

Replace arch with the architecture of your machine (amd64, x86)

Why does the image installation process take a very long time?

Try temporarily disabling any anti-virus software. Windows Defender is known to slow down the process quite significantly. If this doesn't help, then the target drive may be too slow.

OK, but flashing Raspberry Pi OS or any other Linux distro is waaaaay faster. Are you really telling me that the drive is slow?

Sort of. Linux distros for Raspberry Pi usually come packaged in the .img format, which is a sector-by-sector copy of a disk drive. In other words, someone has shared an image of their SD card. (which, by the way, is an illegal thing to do for Windows, due to copyright reasons)

Now, why is this faster to install?

It's faster to install because an .img file is copied sequentially to your drive. Very cheap or old devices usually have decent sequential speed, but poor random I/O performance. The latter is what matters for Windows images, as they're file-based rather than sector-based.

Where can I report issues?

For Rockchip devices:



Windows on Raspberry PE-based installer

Why does the installation fail with code 121 (The semaphore timeout period has expired)?

We've seen this happen on drives that are too slow (e.g.: SD cards that are not A1-rated or better). The only solution is getting a drive that has better random I/O speeds.


Is Raspberry Pi 5 or newer supported?

The short answer is: no, we don't offer support for Raspberry Pi boards anymore.

There have been some efforts in this direction through, which does allow Windows 11 to boot with basic hardware support, but there are no plans to improve it any further.

We strongly encourage you to contact Raspberry Pi (or post to the forums) and let them know that you care about official Windows and UEFI support on their boards.

We also suggest looking into Rockchip boards instead if you're interested in Windows on Arm development, as we mostly focus on that today and believe they provide better value.

Does Windows 11 work?

All builds of Windows 11 can run on Rockchip RK3588 devices.

Windows 11 build 25163 is the last one than can boot on the Raspberry Pi 4 and older.

Recent insider builds no longer work as they make extensive use of the new atomic instructions introduced in ARMv8.1.

The UEFI now supports Secure Boot, and software TPM 2.0 may also be implemented in the future. But there's a new ARMv8.1 CPU requirement which the Raspberry Pi doesn't meet (it has ARMv8.0).

Boards with less than 4 GB of RAM will also encounter the RAM requirement.

The checks are currently present only in setup.exe, but our imager replaces it when doing a clean installation.

Feature updates depend on setup.exe, so you'll have to bypass those checks. More details here: How to perform OS updates.

Where can I find Windows images?

See the Getting Windows Images guide.

How can I update the drivers?

Download the latest driver package ZIP for your Raspberry Pi model from:

To update the drivers from another computer (recommended):

  1. Launch Command Prompt as administrator.
  2. Run Dism /Image:E: /Add-Driver /Driver:"PathToDrivers" /Recurse /ForceUnsigned
    Replace PathToDrivers with the path to the extracted driver package.
    Replace E: with the letter of the Windows partition on your Raspberry Pi boot drive.

To update the drivers directly on your Raspberry Pi (might lead to crashes):

  1. Launch Command Prompt as administrator.
  2. Run pnputil.exe /add-driver "PathToDrivers\*.inf" /subdirs /install /reboot (the device may reboot)
    Replace PathToDrivers with the path to the extracted driver package.

How can I access the boot partition (to edit config.txt or update the firmware)?

There's a tool that can help you do that: Boot partition mount utility

Why am I getting the 'Windows Setup could not configure...' error?

The "Windows Setup could not configure Windows to run on this computer's hardware." error usually occurs when the power was interrupted during the first boot process.

This can be fixed by re-installing the image.

Does the built-in Wi-Fi, Bluetooth, (insert device here) work?

You can find the current hardware support status here:

And no, we don't have an estimated time of arrival (ETA) for anything.

Why am I not able to use any USB devices?

Some outdated guides may tell you to use winpatch. This is no longer required and will break the USB driver.

I keep getting the 'Why did my PC restart?' screen. What should I do?

We don't currently know the exact cause of this issue, but we've seen it happen on slow SD cards / USB drives. So make sure to try a faster storage drive.

Note: sequential speeds don't matter as much as random I/O ones do.

Why drivers that work on my PC don't work on the Raspberry Pi?

Your PC most probably has an x86 Intel/AMD processor, while Raspberry Pi has a totally different CPU architecture.

Only ARM64 drivers are supported on Windows 10 ARM64.

We highly suggest asking the hardware vendor for ARM64 drivers. If enough people contact them, they may prioritize the request.

USB serial drivers?

Silicon Labs CP210x


Direct download:

Manual download (see the Windows Desktop ARM target):


Manual download:

Other devices

Controllers that show up as a standard serial port, like Arduino boards with ATmega16u2, should work too.

You can also use the built-in serial pins on the GPIO header if you have the latest driver package installed.

USB Wi-Fi drivers?

RTL8187-based adapter (made by @emp4u2)

Examples of adapters with this chipset: NETGEAR WG111v2

Other chipsets are NOT currently supported, but feel free to try anyway.

USB sound cards?

Yes. Most of them should work.

Devices that don't need 3rd party drivers are the most likely to work.

Can I run x86 / x64 apps?

Yes, you can run most x86 apps on Windows 10 ARM64.

x64 app support is currently available in the latest insider builds of Windows, and it's significantly faster than the x86 layer.

How can I see the CPU temperature and other hardware info?

Use the PiMon app from the Downloads page.

Why (insert application name here) doesn't work?

Some apps may not work as expected, and we can't really do anything about it. Please contact the app developer / hardware vendor for support.

Only 3 GB of RAM are available. How can I fix this?

  • keep pressing the ESC key after plugging in the power cord, until you see the UEFI setup screen.
  • go to Device Manager -> Raspberry Pi Configuration -> Advanced Configuration and change Limit RAM to 3 GB to Disabled.
  • press ESC several times to go back, then Y to save the settings when prompted and finally reboot the board.

How long does the first boot process take?

This mostly depends on the speed of your boot drive.

Something may have went wrong if:

  • 10 minutes have passed and you're not seeing the spinning dots
  • 1 hour has passed and you're still staring at the spinning dots

How long does the ISO download process take?

It depends on the speed of your internet connection, CPU and storage, thus we cannot tell you an average time.

The ISO download script has failed. What can I do?

In case this still doesn't solve the issue and you're not able to figure out the cause, UUPDump has a Discord server linked in the header of their website. People there may be able to help you.

You can also join the community servers for this project.

How can I delete the ISO download folder? It says that I don't have access.

This is a common issue with scripts from They fail / forget to unmount a WIM image.

To fix this, identify the stubborn mount folder, then execute the following command in a Command prompt window running as Administrator:

  • dism /unmount-image /mountdir:"YourStubbornMountDir" /discard

Can I use virtualization software? (Hyper-V, WSL2)

Not yet. While the CPU supports it, the UEFI doesn't properly inform the OS about this.

Enabling the Virtual Machine Platform will leave the system in an unbootable state!

How can I access the GPIO?


How can I use the built-in PWM controller(s)?


Can I use Windows Update?

See: How to perform OS updates

Does it work on the Compute Module (CM)?

It works on the Compute Module 3.

Compute Module 4 (with or without eMMC) is know to freeze at the UEFI boot screen. See:

Even if you manage to get it booting on the CM4, USB support will require an 1 GB RAM limit. PCIe also won't work.

Will my case fan work?

If it needs any additional installation in Linux, then it will likely not work. The fan control services / scripts must be ported to Windows.

If it's a simple PWM fan, the UEFI can toggle it on boot. You just need to enable this functionality in the UEFI setup menu and connect the PWM signal pin accordingly.

How can I activate Windows?

With a regular license key.

Windows licenses are NOT architecture-specific, so you can use any key that you'd normally use on your PC.

Is this project legal?

See: (some things in that post are outdated, like USB needing patches & such, but the legal aspect is still relevant today)

Also see the replies on this thread:

tl;dr: It's as legal as running Windows on your PC.

We don't share any copyrighted files. You can generate Windows images from files publicly available on Microsoft servers.