CODE:: C0000218

I have a Dell system 8400 with an Intel pentium 4 CPU 3.00GHZ. It comes up with the code:::::: C0000218 and says "When I boot up my Windows XP desktop it goes
straight to Safe Mode / Last Known Good
Configuration / Start Normally menu choice - I
have tried all of the above but it blue screens
every time with the message:


STOP: c0000218 {Registry File Failure}
The registry cannot load the hive (file):
\SystemRoot\System32\Config\SOFTWARE

or its log or alternate.
It is corrupted, absent, or not writeable.

Beginning dump of physical memory
Physical memory dump complete.


Now what do I do to fix this mess?????