I originally wrote this as a Reddit comment, but it was deleted (I guess because it has links? idk), so I'm creating this Gist instead to document how I was able to boot the Windows installer on this laptop.
Note that the easiest solution is to just download the recovery media creator from Lenovo's support site, but I wanted to run the stock Windows installer, so this outlines how to do that.
Here are the steps I took to boot the Windows installer on my Lenovo Yoga Slim 7X (with an ARM64 Snapdragon Elite X CPU). I initially tried using Rufus, and while that drive did show up in the boot menu, selecting it would just hang on the YOGA logo forever.
What did eventually work was manually creating a FAT32 bootable USB drive, here are the steps to do that:
First you'll need to download the Windows 11 ARM ISO.
If you are creating the USB on an x86/64 computer, you'll also need the Windows 11 ISO for your architecture, since you need the bootsect.exe program from it. You can download the ISO at the bottom of this page.
You'll also want a program like 7-zip to extract the ISOs.
Now you can create the bootable USB:
- Format the USB drive to FAT32 (if your drive is too large and Windows doesn't let you, use Rufus, select "non bootable", and use that to format it to FAT32)
- Extract the
boot\bootsect.exefile from the ISO for your current CPU architecture to somewhere on your computer - Use it to make the drive bootable:
.\bootsect.exe /nt60 d:- Run this as an administrator, and replace
d:with your USB drive letter - It should tell you that it successfully updated the bootcode on the target volume
- Run this as an administrator, and replace
- Copy all files from the ARM64 Windows 11 ISO to the root of the flash drive except
sources\install.wim(it is too large for FAT32) - Extract
sources\install.wimto somewhere on your computer (not the flash drive) - Split
install.wimusing this command:dism /Split-Image /ImageFile:"install.wim" /SWMFile:"install.swm" /FileSize:4000 - Copy the
install.swm,install2.swm, ... files into thesourcesfolder on the flash drive in place ofinstall.wim
That's it, plug the flash drive into the laptop, turn it on while holding F12, and you should be able to select the flash drive from the boot menu and boot the Windows installer.
There is one issue that you'll encounter after installing Windows, which is that (at the time of writing) Windows does not include wifi drivers for the laptop, so you can't connect to the internet to download all the other necessary drivers.
I found a copy of the correct wifi drivers on Dell's site, you can download them here. If that link ever stops working, just look for the ARM64 drivers for "Qualcomm FastConnect 7800 Wi-Fi".
You should put the driver installer somewhere on your USB so that you can install it once you've installed Windows. To do this, go through the Windows install like normal until you get to the screen telling you to connect to the internet, then press shift+F10 to open a command prompt. From there you can run explorer and/or run the driver installer you downloaded. If you don't see your USB drive, it's probably because it hasn't been assigned a drive letter. You can assign one using diskpart or diskmgmt, and then you should be able to access files on the drive and run the installer. Once you're connected to the internet, Windows will automatically download all the other drivers for the laptop (including the Lenovo-specific ones like for the hotkeys). The only thing that doesn't get installed is X-Rite Color Assistant, so get that from the Lenovo support site if you want it.