1. Overheating. Check the CPU temp as, if it gets to 80c or above, the system might shut itself off to minimize damage.
2. Conflicting drivers. Check the device manager to see if there are any conflicts or problems. This can sometimes cause the blue screen of death.
3. Low or unstable battery. When battery power is low or the battery cannot supply a steady stream of power, problems will occur.
I'm not an expert with laptops (I don't own any myself), so I'm a bit limited on that front.