DRIVER_POWER_STATE_FAILURE error is mostly occurs due to any faulty hardware device, inappropriate or incompatible device drivers, etc. Try to boot the computer with Windows 8 bootable installation media to enable legacy boot menu from the command prompt. This will help Windows 8 boot in safe mode. For further help, follow the link given below to resolve this issue. http://www.tomshardware.com/faq/id-1653253/fix-driver-power-state-failure-windows.html
Hope this helps.