Unable to install Windows Update on Microsoft Surface Pro X

I have a new Microsoft Surface Pro X 128GB. When I tried to do a Windows Update installation via restart, it fails to install, with the error code 0x800f0922. I have searched for a solution for this, and it seems to be because the reserved system partition is too small (260MB in my case instead of the recommended 500MB).

The "Disk Management" section shows the partition layout as follows:

• Disk 0 partition 1 - EFI System Partition - 260MB
• C - 118.46GB
• Windows RE tools - 410MB

I want to extend the System partition to 500MB, but I don't know of a way to do so. I have tried shrinking the C drive to add unallocated space, but that space comes out to the right of the C drive, and can't be used.

I've tried downloading third-party apps, such as EaseUS Partition Master and AOMEI Partition Assistant Standard, but when loading those apps, I get errors such as

• "Load driver failed, please reinstall the program." (which I did, to no avail)
• "Disk device not detected by EaseUS Parition master.."

I am out of ideas for what to try at this point. Does anyone have a suggestion?

UPDATE:

After discussing with @harrymc, I restarted my computer (without doing anything to it). Apparently the Windows must've corrupted itself somehow, because restarting it error into a green screen "INACCESSIBLE BOOT DEVICE". It's unclear to me how that happened, because I was restarting it many times right before this point without an issue. And I have not performed any action that I suspect would corrupt it.

I created a bootable USB device (from another Windows computer with AOMEI PA), and under the "Automatic Repair" option, choose to boot from USB. However, that doesn't seem to take, as the Surface Pro X continues to be stuck in a bad boot loop.

What @Ramhound suggested about reserve partition is good info, but I don't have a way to log into the machine normally to look at the logs.

You will need a bootable partition editor, since the C partition cannot be moved while Windows is running.

Your problem is that with the ARM processor of the Surface, you won't be able to use Windows software that wasn't compiled for it.

I don't know of a Windows partition editor for ARM, but there are Linux Live USB that are made for it. An example is Kali Linux ARM Images. You will need to try running the Linux Live boot on the ARM and solve problems as they arise. This is known to work, so you could find resources on the internet for solutions (or ask on our site). A possible example is the need to disable Secure Boot in the BIOS (if this is possible on your device).

I suggest before starting to take good backups, since errors while changing partitions can destroy the disk, up to taking a backup image of the disk.

The procedure to follow:

• Boot Windows and use Disk Manager to reduce the size of C by 500 MB. Check that you have now created unallocated space of this amount at the end of the partition.
• Boot Linux live and use the included disk editor, perhaps parted or gdisk
• Move C to the right so the unallocated space now follows the EFI partition
• Enlarge the EFI partition to contain this space
• Reboot Windows.

In case of a problem that will make Windows unbootable, you should also prepare a boot installation USB for the latest version of Windows 10, with which to do Startup Repair.