STOP: c0000218 unknown Hard error

I have got a desktop computer which is restarting continuously and access the Windows Start up on the screen. But once getting past the Windows Start UP screen it will go to black screen and will show list of all drivers loading. After that the pc shuts down and continues with the same symptom of shutting down and then reloading again and never reaching a complete boot up. The same issue happens when trying to start in Safe Mode or any other mode. After this is going for some days, I get a blue screen of death with this STOP: c0000218 unknown Hard Error, unknown Hard error, beginning dump of physical memory". Can anyone tell me how to solve this problem? Thanks

If the startup menu appears then ensure that you have selected the Safe Mode option from the menu. Incase that does not work, then try to select the "Last Known Good Configuration" option. Incase both wont work, then you can try to Repair Install Windows XP as per the instructions given in the below link:

http://support.microsoft.com/kb/917964

Thanks for the reply. But I am not able to get that far. I cannot get to the point of selecting Safe Mode and neither can I choose the Last Known Good Configuration. So, when I reboot the computer, then the below message appears:

PXE-E61: Media test failure, check cable
PXE-M0F: Exiting Intel PXE ROM.
Boot failure: System Halted

Any ideas?

Try to look at the below link giving information about the Stop: 0x0000218:

http://support.microsoft.com/kb/822705/en-us