I bought my Samsung ATIV 500T back in 2013 in Paris. It was preinstalled with Windows 8 Home. I soon upgraded it to Windows 8 Professional to be a part of the work domain. And later to Windows 8.1 and later to Windows 10.
I am still very happy with it and it's pen-OneNote combination is still bringing a lot of surprise to whoever is near.
Once I incidentally tryied to install SQL Express to it and it was very bad decision. I create a Windows Restore Point before so it was quite easy to roll back.
But few days ago I tried to do the factory Reset and ended up with unbootable device. There seems to be no "Boot from USB" so I have had to come with another idea.
To keep it simple:
- prepare a USB stick with Windows 8 32-bit first (the original operating system for Samsung ATIV 500T)
- turn 500T off
- stick the USB in
- Hold Volume Up + Power
- Keep Volume Up hold until you see "Wait..."
- Note there is no "Use a Device", but you can go to "Advanced"
- Run "Start command prompt"
- find the USB stick (it was
D:for me) - run the Windows installer
D:\setup.exe - Install Windows 8
- Update your drivers (hope you saved them first when you bought your 500T)
- remove the USB stick
- put Windows 10 32-bit on the USB stick
- run upgrade to Windows 10 from Windows 8
- enjoy

@AbdelrahmanGamee You need to use a FAT32 USB.
Connect a USB dongle and press F10 during boot.
Select the USB drive and it might get stuck, reboot it pressing the power button and repeat the F10 process. Now it will show a windows boot manager.
Select the new option and wait. You should be able to remove the USB.