Big Registry - Delete Commands To Get Back

I came back later, turned it on, and BAM! I ended up with a blue screen whining about not being able to load a registry hive, C:WindowsSystem32ConfigSOFTWARE in particular.So I google searched on my brothers machine for a way to fix it, which pretty much involved loading up 6 annoying Win XP boot floppies that takes days to load (Ok i'm exagerating a little there....) and getting into the Recovery Console to perform some copy/delete commands to get myself back to previous registry files.
Which to my dismay, I found out that it took me back to the stone age (like when XP was first installed, infact to me it seemded like it had gone back even further).