|battery life is finished|
Are you referring to the coin cell on the motherboard?
This is normally a CR2032 battery. Some motherboards may use other types.
If it is really finished then it will not be able to retain the BIOS CMOS settings. Under those conditions the CMOS settings could be all over the place. Most motherboards would thus struggle to boot correctly. So first replace the battery and then boot straight into BIOS and either set it to failsafe defaults or optimum defaults and then try to reboot.
If it is indeed the battery then your motherboard will once again function correctly.
NOTE: A good battery should be at least 3.0V and you can measure it with a volt meter.
☺ When everything else fails, read the instructions.