Microsoft has run into a rather embarrassing hiccup lately that means Windows Update fails to properly check there’s enough space on local storage for a Windows 10 patch before it downloads and attempts to install it. This can lead to a potential scenario where Windows 10 fails to reboot properly due to a failed partial update attempt.

It’s a fairly straightforward problem with Microsoft saying “Windows Update does not check systems for adequate space requirements before it initializes.” Microsoft’s solution to the problem isn’t so straightforward though, asking users to clear all temporary files and to keep themselves aware of when storage space may be limited.

On top of this, Microsoft has taken the audacious move of reserving another 7GB of your available storage. If you are running Windows 10 and have the latest Windows update (Version 1903 - 19H1), Microsoft will have snaffled up around 7GB of your storage on top of your current installation.

The reserved storage is basically untouchable. There is no feature within Windows 10 to disable this process and so once you receive the Version 1903 - 19H1 this space is permanently gone. For a lot of people this isn’t going to be a major issue, but for folks with limited storage such as OS installations on small SSDs, or Windows 10 powered notebooks and tablets, this can quickly become a pain. Some Windows 10 laptops, for example, come with 32GB storage total. Microsoft is swallowing up 22% of their storage overnight.  I haven't been blessed with this particular update just yet, although I've somehow got 43GB occupied by system files and reserved files which already sounds heinously large.

Microsoft’s reasoning for the change is as follows: “Through reserved storage, some disk space will be set aside to be used by updates, apps, temporary files, and system caches. Our goal is to improve the day-to-day function of your PC by ensuring critical OS functions always have access to disk space.

Without reserved storage, if a user almost fills up her or his storage, several Windows and application scenarios become unreliable. Windows and application scenarios may not work as expected if they need free space to function. With reserved storage, updates, apps, temporary files, and caches are less likely to take away from valuable free space and should continue to operate as expected. Reserved storage will be introduced automatically on devices that come with version 1903 pre-installed or those where 1903 was clean installed.”

This doesn’t sound like the greatest way to go about such a change, particularly springing it upon users without warning. There’s certainly an argument to be made that the size of a W10 installation is ballooning out of control, particularly for those with smaller storage drivers.