Why is laptop getting automatic shut down?

This is a very common problem i deal with all the time at my shop. The bootloop usually comes from two different issues. First issue is windows corruption. For example if a windows update got cut off or the computer got shut down multiple times incorrectly. The second usual issue is a bad hard drive. Now lenovo recovery is done actually with a button on the side of your computer depending on the model. If you take a paper clip and look on the left and right side of your laptop there should be a tiny hole. Sometimes the whole has an arrow next to it. IF you turn the pc off then insert a paperclip into that hole it will turn on and give you options for boot and recovery. Second option you have is making a windows bootable iso. There are plenty of videos on how to do that. You just need a 32GB flash drive and you can boot into that and reload windows. If that dosent work then you most likely have a bad hard drive.