En DOS, sous Win9x, regedit /C fichier.reg
Ce dernier est censé contenir la totalité du registre.
Sinon, il existe des freeware permettant de faire du search and replace dans le registre mais j'ai rien sous la main.
tu peux regarder ici pour "registrar lite"
http://www.resplendence.com
Registrar Lite for Win95/98/2000/NT is a freeware, new generation
registry editor that comes with a basic set of tools that make your
registry editing life a lot easier. It could be an excellent
replacement for RegEdit which come shipped with Windows. It allows
cutting, pasting, copying, and moving of keys and values as if it were
Windows Explorer. It has search and replace capabilities, a bookmark
editor that optionally colors bookmarked keys and adds key descriptions,
flexible value editors that allow importing data from files.
Additionally, it allows importing and exporting of .reg files and it has
remote update capabilities.
Pierre.