Setup options include Windows 10, Ubuntu, Linux, or dual booting all three.
Setup options include Windows 10, Ubuntu, Linux, or dual booting all three.
You mentioned a device running Android 4.4.4 with a stock ROM, while another version available online uses Windows 8.1 as its stock ROM.
It seems both operating systems were sent to the same device, possibly using the identical BIOS. Give it a shot and check if it functions properly.
It's not just Office 365 since it's web-based. You can also use LibreOffice or Apache OpenOffice. For the tablet, going with Windows 10 is probably the best choice, as mentioned by Nayr438.