One of the many questions swirling around Windows 10 in these confusing days leading to the launch is how it will handle upgrades on storage-constrained Windows 8.1 devices like mini-tablets and mini-laptops. But recent builds finally include the functionality I first heard about back in January. So now we can finally see how it works.
I heard about this change last week from a few readers while I was away in Ireland. I’m not exactly sure when Microsoft added this functionality, but if you’re on the most recent Fast Ring build (10162 at the time of this writing, though I’m expecting a new build as soon as today) you should be able to test it now.
First, be sure to make a recovery drive and to do so on a USB stick that is big enough that you can “back up system files to the recovery drive.” I’ve found that this process is especially dicey on 16 GB mini-tablets, so don’t skip this step.
And that’s the issue with these devices: Windows 10 needs several gigabytes of free space during install, and then several gigabytes of space to store the Windows.old folder, which can be used for a few weeks after the upgrade to revert back to Windows 8.1. So now Windows 10 Setup will examine your free storage space and note that your PC requires removable storage if there isn’t enough.
This can be USB- or microSD-based, as I was told back in January.
One interesting possibility, of course, is to use the Setup media if you are using a USB-based Setup device (as you can if you downloaded a Windows 10 ISO). Or you could use a microSD card, which would make even more sense since you want to keep the Windows.old folder with the device going forward. You’ll need an SD card anyway: storage constrained devices with a compressed OS, which are devices like the WinBook W700 or the many HP Stream laptops and tablets, or similar, often come with just 16 or 32 GB of internal storage. After fully updating the WinBook W700 via Windows Update, but before installing Office via the bundled Office 365 Personal, this 16 GB device only has about 2 GB of free space left. That is ridiculous and unworkable.
Anyway, once you’ve specified a storage device to use, Setup continues normally and works much like it does on other PCs and devices (though these mini-PCs, which are usually Atom-based, are slower).
I’m going to test this process on multiple storage-constrained devices today if possible, and I’ll update here if I run into any weird issues. But so far, it looks like Microsoft has effectively solved the problem with such devices: you just needed removable storage.