http://annoyances.org/exec/show/registry is a good site with beginner registry stuff (and lots of other Windows tweaking things too). Your registry in WinME/98/95 is stored in the hidden read-only system files system.dat and user.dat in your Windows directory I think. I don't even know if Windows will let you touch those files, unless you boot to DOS. When I used to back them up I'd usually boot to pure DOS, then use the ATTRIB command to un-hide, un-system, and un-RO them, then do what you need to do to them, then re-hide, re-system, re-RO them.