During the last boot_up your system hung for improper freguency combination. the system is Working in safe mode. to optimize the system performance and reliability, make sure the freguency combination conforms to the specification of your CPU, DIMM and other connected devices. now every time i try to change it & save it. it will turn off & doesn't come back again.. i don't know what the problem & what is the Cpu External Freguency for it there is so many # plz help me fix it.