Do you carry the laptop around with you in a bag or something? At the datacenter I work at I had someone here have the same issue, and it got worse over time. The motherboard had bent while being slung around on the backpack. It flexed just enough (not much) to flex the motherboard and cause horrible issues. The laptop would randomly shutdown, even when sitting on a stable flat surface. It would shutdown anytime between 5 seconds to 30 minutes.

I called Lenovo support and they came out and replaced the motherboard the next day free (due to accidental protection).

You also might want to try running memtest 86 on the laptop, and I know it might be a stretch, but you might want to run a chkdsk on the machine too.

If you have any questions about this, please let me know!

Do you carry the laptop around with you in a bag or something? At the datacenter I work at I had someone here has had the same issue, and it got worse over time. The motherboard had bent while being slung around on the backpack. It flexed just enough (not much) to flex the motherboard and cause horrible issues. The laptop would randomly shutdown, even when sitting on a stable flat surface. It would shutdown anytime between 5 seconds to 30 minutes.

I called Lenovo support and they came out and replaced the motherboard the next day free (due to accidental protection).

You also might want to try running memtest 86 on the laptop, and I know it might be a stretch, but you might want to run a chkdsk on the machine too.