If you see Error 1962, No operating system found, Press any key to repeat boot sequence when you start your Lenovo computer, see this post.

When you turn on your Windows computer and receive the message that says The operating system did not shutdown cleanly, this post will help you fix the problem.

Microsoft's Windows is experiencing a global outage that has left millions of users seeing the dreaded blue screen of death or repetitive boot loops.

I have solved the "No operating system found" by replacing the boot.ini file with a known good boot.ini. Not sure if that would work with your problem.