Hi, Jon here. So, I'm looking at an older-friends PC, cause, she said she was having a prob with "e-mailin"(her words) but when I get it home and power it up, received error msg: "stop: c0000218 {registry file failure} the registry cannot load the hive(file):\systemroot\system32\config\security or its log or alternate, it is corrupt, absent, or not writable."
What do I do? Is it a virus, or is it something she did? Fix?

For those kinds of errors (and many others) I just Google them to get results.
Try this and see if it's something you'd want to tackle;

How to Troubleshoot a Stop 0xC0000218 Error Message