There are several threads that are discussing how to install Windows 10 to a MicroSD card: Win10 Installation Issue (seeing other drives) Cannot Install Windows 10 on micro SD Card. No drive detected! How to install Windows 7 or 10 onto a micro SD card? And I posted reply talking that it is possible to achieve it by using Windows To Go or VHD. Someone with 8GB eMMC might need it because the built-in eMMC is not enough for Windows and this would be a solution without attaching a HDD/SSD. Now I have reached it successfully and would like to share the method here. The tool used is WTG Assistant (source) and it has a support forum. Requirement: A USB disk or MicroSD card above 16GB (according to my trial 16GB is no longer feasible for Windows 10 Version 1703 CN); WTG Assistant. Windows installation image(Windows7、Windows 8、Windows8.1、Windows 10、Windows Server 2012、Windows Server 2012 R2) Step 1: Mount the Installation image (Windows 7 is not recommended). This can be done by double clicking the ISO file above Windows 8. Step 2: Run WTG Assistant220.127.116.11 (file name wintogo.exe), it might be in Chinese so you might need to change to English (alought I think the English translation doesn't make much sense and it makes GUI in a mass). Pop-Up will then say programme will be restarted but it never worked so you have to run it again manually. Step 3: Choose install.wim. It is located in the virtual drive:\sources mounted just now. Choose target drive and this should be a USB disk or MicroSD card. On the right side Com. tab, I chose VHDX and Windows 10 Pro under Ver. option. UEFI+GPT is also ticked. (optional) Under VHD tab, I changed the name of the VHD file and change its size by moving slider to right side. Some options are covered by the long letters but they don't need to be modified. FYI: VHD partition table format is GPT and VHD Temp Folder is somewhere in current OS temp folder. See below. Step 4: Under Sys tab, the Fix Letter is ticked by default. I also tick Hide Lcl Disk to hide local disk when booting from this VHD system. More information can be found in the support forum. (optional) Under Disk tab, there is an option called No temp, means creating VHD directly on removable disk. If you think your device is fast enough then it should deserve a try (it saves time). Step 5: Click Go. Two warning windows are appeared. Confirm twice. After some moment it would finish dumping. (optional) For PRO user, the partition structure of the disk looks like this on my 64GB MicroSD card.There is a main partition that stores VHD file, a EFI partition~100MB storing EFI boot file and a spare partition~4.5GB. I don't want to 'waste' it so I move EFI partition to the end and merge the 4.5GB space to the main partition. Warning: Incorrect operation may lose your data! Perfect! Now move to UDOO x86. Step 6: Choose boot device, EFI SD/MMC Card (AFGCE). The booting process should begin.