If the BIOS update is stuck at 0 or 100 %, check if your motherboard has a Self-Healing BIOS feature and then follow these ...
HP confirms its BIOS update is breaking expensive workstations, sparking outrage among users. When you purchase through links ...
If your iPhone isn't responding, and you're not able to power it off and then on again, you can force restart it to hopefully fix the issue.  Forcing a restart is different from a normal restart.