Hello Andy!
Thank you so much for doing that for me.
Using another hard-disk/computer is another good way of achieving the same result. Well done :)
You have correctly understood Repair Install. Some people call it an Upgrade Install, In-Place Upgrade, etc. You may be more familiar with those terms, but it is all esentially the same thing, which is insert DVD, and from within Windows perform the upgrade to your same OS and edition - exactly what you did.
Unfortunately, whilst it did help to get it further, the Repair Install did still fail.
Don't worry about Windows Update, SFC, etc. The registry doesn't match your computer, so they are pretty much guaranteed to fail.
Unfortunately, things look pretty bleak now. Your corruption is massive, and our last ditch effort, whilst it did help, didn't allow the Upgrade Install to succeed. The only real advice I can offer now is to Clean Install, losing everything
(unless you have a very old image of your system you could grab an old non-corrupt COMPONENTS hive from - it might just work)
But, and I am really, really sorry, I am not able to fix this
Richard