Got the lovely message:
"The registry cannot load the hive (file): \SystemRoot\System32\Config\SOFTWARE or its log or alternate"
Of course I haven't backed the registry up. That takes work. Or made a system restore point. That takes more work. And I've never had to restore a registry before in my life. See that's good IT work right there.
Have read the following article at https://support.microsoft.com/en-us/kb/307545
and the questions are based on that.
Have booted into the recovery console and identified correct drive and folders. Now for the questions.
Can't make a directory using md or mkdir. Don't really need to make a directory but someone might know why this is so for knowledge purposes.
Have verified that I have a repair registry (\WINDOWS\REPAIR\) when I created Windows XP so I can copy those across but noted that in \WINDOWS\SYSTEM32\CONFIG\ I have *.bak files from 10 days ago. Can I use these for my registry files rather than using the files from \WINDOWS\REPAIR\ ? Two or three of the bak files seem to be the same as those with no bak. The other bak files have wildly different sizes.