hey,
If you powered off your PC during the INSTALLATION process, its very likely your operating system has corrupted.
The issue here is that during the install process, windows deletes the old version and then replaces it with the new update you just downloaded. When the PC powered off, you prevented the new version of windows from being presented onto your PC leaving the some files half transferred etc. This results in corruption.
If you have a Windows 10 Disc you can quite easily repair / install a fresh version of the newest Windows 10 in a short period of time as long as you have your prepaid Product key.
alternatively, you can make a bootable flash drive and install the latest windows 10 ISO image from Microsoft's website and install from there.
(both ways require the product key)
I hope this helps