I finally did it! Just more than a week ago I bought myself the Sansui WIB802 windows 8.1 tablet. Almost straight after unboxing I started the Windows 10 upgrade. That was a mistake, the system upgraded but nothing worked, only usb. No touch screen, no bluetooth, nothing. I then rolled back to Windows 8.1. Started reading a little and found this forum among others. I then backed up my drivers and tried the upgrade again, it would not work because there was not enough space on the c:. Although there was 2.8GB free, W10 required onother 3GB to keep my files. This is when I noticed the W10 upgrade actually removed the recovery partition and made it a system folder on c:.
So, I downloaded the W10 iso on an SD card and started the installation saying keep nothing. The upgrade worked until 55% and then stalled. I switched of the tablet and let it roll back to W8.1. It then showed me that it faled on code 0xc1900101-0x30018. i followed all the advice... disable bluetooth, everything. I actually started looking into editing the disk from the UEFI!
Well today I actually got it right to boot from a USB drive and almost did a format-install, but that would mean I would have to buy a key for W10. So I decided instead to plug in a powered hub and do the upgrade from within W8.1 again, but this time running from the USB drive. It required a further 10GB space, I plugged in a 2TB external HDD. The upgrade went through keeping files and setting (drivers) without issues! the trick is to use usb. the upgrade kept stalling because there are no native drivers for the card reader. So, no SD card, upgrade from USB! It works!
