HKEY_CLASSES_ROOT
Contiene información de las asociaciones de archivos y los datos
de OLE específicos de cada aplicación.
De hecho es un puntero a HKEY_LOCAL_MACHINE\SOFTWARE\Classes
The HKCR root key first appeared in the Windows 3.1 Registry; Microsoft
migrated HKCR to the NT 4.0 Registry for compatibility purposes. HKCR consists
of two types of information:
-
file extension associations,
-
and OLE class registrations.
A key exists for every registered filename extension. Most keys contain
a REG_SZ value that points at another key in HKCR containing the association
information for the class of files that extension represents. For example,
if you install Microsoft Word, the .doc subkey has an unnamed value, "Word.Document.6".
If you look at the Word.Document.6 subkey, you find an unnamed value that
describes the file type (which Explorer's file-association window uses)
and keys that associate that type of files to icons (DefaultIcon); other
keys specify dynamic data exchange (DDE) commands created whenever you
open, create, or print Word.Document.6 files. Keys without defined unnamed
values have DDE command information stored in subkeys.
HKCR keys such as Word.Document.6 also contain OLE registration information.
That way, OLE client applications can look up and establish communication
with OLE server applications to support functionality such as inserting
an Excel spreadsheet into a Word document. CLSID subkeys store registration
numbers as very long representations of OLE registration identifiers.