I accidentally shut down my Lenovo laptop during a factory reset?

Most lenovo laptops have a OneKey Recovery button, either in the form of an actual button on the keyboard typically next to the power button, or a small paper clip-sized hole. OneKey recovery allows you to access the laptop's recovery partition, provided it's intact.

Turn the laptop off completely and then press the OneKey button, which is usually labeled by a symbol that looks like a sort of arch with two arrows. It should turn the computer on and bring you to a menu with a few options. You want to select system recovery and it should boot you into a menu where you can run another factory reset to get the computer back to where it should be.

Here's Lenovo's support article on OneKey Recovery

Start a new factory reset and don't touch it til its finished. You should also have OneKey recovery via the other power on button(tiny one) next to usual power on button. This will do a full install so you may lose all your previous files.

Perform another factory reset. There's usually a message during boot up to press an "F Key" to do a factory reset, which directs the computer to a hidden partition where the factory original is stored.

Try doing a factory reset again.