Hello!
Okay, I have a Acer W3-810 which I am trying to upgrade to Windows 10. Here are the facts:
- System has over 8gb free in the C drive.
- Downloaded Creation Tool on my main laptop and created a USB (32gb) with installation media using the wizard.
- All recent Windows updates installed on tablet.
- Used the USB to upgrade to Windows 10 - with updates installed.
- First major failure the installtion reached 71% (installing features and drivers is at 91%) and failed.
- I restarted tablet and Windows 8.1 restored itself
- This was the error: 0x80070004 – 0x3000d. The installation failed in the First_Boot phase with an error during Migrate_Data operation
- Searching the internet did not provide too much help on the exact cause of the error but I did delete C:\$windows.~BT and ran a check disk thingy (CHECK EDIT BELOW FOR WHAT I DID HERE) to scan for any driver issues & restarted.
- Once restarted began the installation process with USB.
- Somewhere after about 20% (copying settings), the tablet restarted itself and restored Windows 8.1 throwing up this error: 0x80070070 - 0x2000C The installation failed in the SAFE_OS phase with an error during APPLY_IMAGE operation
- Again, researched issue, ran some more check disk operations, deleted Avast!
- Restarted and began installation again!
- Then the installation fails again somewhere between 10/25%, tablet reboots and restores Windows 8.1
- So then I go into the BIOS and turn of the UEFI Secure Boot (as many have recommended that this works)
- Restart installation, fails again somewhere after 20%
Now, a lot of people have suggested that ALL USB devices be removed whilst upgrading to get about the seond error, however since I am using the USB to install Windows 10, I'm not sure how to work around this. Unless the 8.4gb I have free is going to be enough?
Secondly, if by some miracle I fix the SAFE_OS failure, what's with the MIGRATE_DATA failure? And why did I manage to get ALL the way to 77% the first time I managed to get the installer to work on my tablet and now it will barely get to or past 20%
Any help with this would be greatly appreciated, and I'll be happy to try and provide more information where possible.
Thank you! 
EDIT: The check disk thingy I did after the 71% failure I found here (rundll32.exe pnpclean.dll,RunDLL_PnpClean /DRIVERS /MAXCLEAN)