Windows.XP.in.a.Nutshell.1002005.2Ed [Electronic resources] نسخه متنی

Chapter 8. The Registry

The Windows Registry
is a database of settings used by Windows XP and the individual
applications that run on it. Knowing how to access and modify the
Registry effectively
is important for troubleshooting, customizing, and unlocking hidden
features in Windows XP.

An amazing amount of what one might assume to be
"hardwired" into Windowsthe
locations of key directories, the titles of on-screen objects such as
the Recycle Bin, and even the version number of Windows XP reported
in Control Panelis actually the product of data stored in the
Registry. Change a setting in the Registry and key parts of your
system can be affected; for this reason, Microsoft passively
discourages tampering by providing only minimal user documentation on
the Registry Editor, and no documentation at all on the structure of
the Registry itself.

Despite the enormous potential for harm, the Registry is fairly robust, and for every entry that you can wreak havoc by changing, there are hundreds that you can change with impunity. Nonetheless, you should back up the Registry files before making significant changes with Registry Editor. See Section 8.5, later in this chapter, for details.

The Registry is normally consulted silently by the
programs (such as Explorer) that comprise the Windows user interface,
as well as by nearly all applications. Programs also commonly write
varying amounts of data to the Registry when they are installed, when
you make changes to configuration settings, or just when they are
run. For example, a game like FreeCell keeps statistics in the
Registry on how many games you've won and lost.
Every time you play the game, those statistics are updated. For that
matter, every time you move an icon on your Desktop, its position is
recorded in the Registry. All of your file type associations are
stored in the Registry, as well as all of the network, hardware, and
software settings for Windows and all of the particular configuration
options for most of the software you've installed.
The settings and data stored by each of your applications and by the
various Windows components vary substantially, but more often than
not, a given Registry setting will appear in plain English, making it
relatively easy to decipher. There are also several advanced
techniques that not only help to identify more obscure settings, but
allow you to use undocumented settings to uncover hidden
functionality.

Microsoft
provides the
Registry Editor
(regedit.exe), which is used to view and modify
the contents of the Registry. Don't confuse the
Registry with the Registry Editor; the Registry Editor merely reads
and writes data in the Registry like any other Windows application.
When you start Registry Editor, you'll see a window
similar to the one in Figure 8-1.

Figure 8-1. The Registry Editor uses a familiar interface
to manipulate unfamiliar data

The
organizational structure of the
Registry is hierarchical, so Microsoft chose an interface familiar to
anyone who has used Windows Explorer. As in Explorer, there are two
panes: the folders (keys) are displayed in a cascading tree on the
left, and the contents of the currently selected key appear on the
right. Use the small plus (+) and
minus (-) icons to expand and
collapse the branches, respectively; cursor keys also work here.

While the interface elements might appear familiar, the
data that is manipulated with Registry Editor is nothing like the
files and folders we deal with in Explorer. Although you can
certainly dive in and begin wading through the thousands of keys and
values in the Registry, you're not likely to find
anything of value until you arm yourself with a basic understanding
of the way data is stored and organized in the Registry. And, of
course, this is the focus of the next few sections.