|Sounds like a hardware problem - guessing the motherboard or processor or both are dying. But, possibly something else. If this is a desktop machine, open the case and disconnect hard drive(s) and optical drives and try booting again. If still the same, try to locate the clear cmos jumper on the motherboard (usually labelled jbat or jcmos or cmos reset). Usually 3 pins with 2 covered. Remove cover and cover the 2 currently uncovered then put it back as was and try booting again. If no good again, motherboard (or processor or both) likely culprit - you'd be best getting professional advice if you want to repair the machine (could also be power supply).|
If its a laptop, try removing the battery and booting with just mains power. Also if no good, and you can find where the hard drive is, try removing that and booting again, see if it gets any further (if it does, suggests hard drive is problem). resetting cmos is more problematical in a laptop - really need a manual to find out where/how to do this.