Does it boot all the way? Are you able to do anything in Windows?

If so, try Settings > Update & Security > Recovery > Reset This PC.

Otherwise you should probably connect the drive to another computer and try to copy off the user data, then put the drive back in the original computer and do a clean install from external media.

The problem you describe with the power supply sounds like a hardware problem to me, not corruption or infection. My guess is that the power supply is bad.

http://www.techadvisor.co.uk/how-to/windows/how-reinstall-windows-reinstall-windows-10-reinstall-windows-10-3535423/