Registry files (.reg), which are generally produced by exporting a key from regedit, can be imported into a Windows Installer database, such that the registry tables (Registry, RemoveRegistry) contain the relevant values.
Because rows in these tables must be associated with a component, InstEd allows importing of registry files from Component nodes in the Components or Features view.
To import, select the menu option View->Components, right click a component node in the treeview, and select Import .reg file.
All the resulting entries in the registry tables will be attached to the selected component.
InstEd does not currently do any analysis of the registry data. So COM advertising extraction, and possible replacement of paths according to the Formatted rules, are not performed.
Note that the registry file must be encoded in Unicode (little endian). Notepad can convert ANSI or UTF-8 encoded files to Unicode (SaveAs->Encoding). Regedit exports to Unicode files by default on NT systems.