i have downloaded windows 10 upgrade file but the battery ran out during installation

[Priyal]

Windows 10 upgrade remained incomplete as my laptop got powered off bcoz of low battery.

 

[Colif]

If you have a mobile device, you should always think of its charge state before updating os. Its always important to be plugged into wall.

ON another pc, download the media creation tool again and make a DVD or USB instead of updating it. The DVD much more useful as it survives a power outage so can be used multiple times.

I think you probably need to do a fresh install now so follow this: http://www.tenforums.com/tutorials/1950-windows-10-clean-install.html

or you can run recovery if your laptop has it ands then use the media creation tool to upgrade again.