We have many HP Stream devices and these have only 32 GB of storage. Windows 10 is a compact operating system and this is enough, particularly if you are mainly using them with cloud services. However there is a known bug in Windows 10 where sometimes Disk Clean-up (from disk properties or Settings > Storage) sometimes fails to remove temporary files. By using WinDirStat I found that I had over 4GB of un-deleted Windows updates. To do a brute force delete* of all temporary files open a command prompt as Administrator and,
rem delete temporary files del c:\temp\*.* del %temp%\*.* del C:\Windows\Prefetch\*.* rem Stop and restart the Windows update service Net stop wuauserv cd %systemroot% Ren SoftwareDistribution SoftwareDistribution.old Net start wuauserv del c:\softwaredistribution.old
* at your own risk, feel free to make a backup first.