Not enough disk space, that was the message that the installation process gave me when I tried to update my tablet using the Windows 10 update App. It just said that it needed 6GB of disk space, then I just kept getting an error in Windows Update.
After my best cleanup attempts, and removing almost all the apps, programs, and Windows update files, I was left with just 2GB of free disk space. Certainly not close to the 6GB that the installer required.
What I did to get it to work was to refresh Windows, keeping my apps and settings. This left me with 3GB of disk space, still not enough.
I decided to download Windows using the Windows 10 media creation tool to give it a try - make sure to choose the 32-bit version, and chose the SD card as the target media. I had to do this using my desktop computer as it still required 6GB of free space on the C: drive.
I then inserted the SD card into the tablet, started the installer. It still asked for 6GB of free space, or an external medium with 8GB. I chose the SD card as the external medium, and it worked!!
I now have a brand new installation of Windows 10 on my Archos 80 Cesium tablet.