from
The Free On-line Dictionary of Computing (8 July 2008)
Windows Registry
registry
<operating system> The database used by {Microsoft} {Windows
95} and later to store all sorts of configuration information
such as which program should be used to open a .doc file,
{DLL} registration information, application-specific settings
and much more.
The Registry is stored in .dat files, one in the user's
profile containing their per-user settings and one in the
Windows directory containing settings that are global to all
users. These are loaded into memory at login.
The loaded data appears as a tree with five main branches:
HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE,
HKEY_USERS, HKEY_CURRENT_CONFIG. HKEY_CLASSES_ROOT defines
file types and actions, HKEY_CURRENT_USER is an alias for one
of the sub-trees of HKEY_USERS and contains user settings that
override the global defaults in HKEY_LOCAL_MACHINE.
The branches of the tree are called "keys" and are identified
by paths like
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion.
Any node in the tree can have zero or more "values" which are
actually bindings of a name and a value, e.g. "Logon User
Name" = "Denis". The value can be of type string, binary,
dword (long integer), multi-string value or expandable string
value.
Windows includes a Registry Editor (regedit.exe).
(2008-01-20)