Most books consider the Registry an
advanced topic, and it is. But the Registry is the heart and soul of
Windows, and it is essentially what makes Windows what it is. The
Registry is a hierarchical database of settings for components—services,
the kernel, device drivers, hardware, the Security Accounts Manager,
software, the graphical user interface, you name it.
When you change things in Windows, you write a
value or set of values to one or more places in the Registry. When you
install a component, it registers itself in the Registry. The main
branches in the Registry are called hives, and each contains a set of branches. Branches contain a set of folder-like structures called keys, and within the keys you find locations that contain name/value pairs where data is stored.
Application developers use the Registry to
read settings that already exist and to write their own. The Registry is
extensible, but it is also optional, and developers aren’t required to
use it. Game developers, makers of portable applications, and certain
Windows components write their settings to files within their own
folders.
The Registry replaces the initialization files
that were used in early versions of Windows. The Registry is why you
can’t simply copy files over to a system folder and have Windows work.
You should exercise
caution when you make any changes to the Registry, because a careless
change to the wrong key can make your system unbootable and will require
Windows to refresh itself. However, there will be times when your
system doesn’t behave properly. In those cases, consult the Windows
Knowledge Base for specific instructions, where you may find information
on how to resolve issues by modifying the Registry.
To alter a value in the Registry
1. Press 
+R, and type regedit. Press Enter.
2. The User Access Control dialog box opens and asks you to elevate your privileges; click OK.
The Registry Editor opens .
The Registry Editor
3. Navigate to the key
you wish to modify by double-clicking or double-tapping the key or by
clicking or tapping the + (plus sign) to the left of the key.
4. Double-click or double-tap the key itself to open the Edit String dialog box.
5. Make your changes, and click OK.
Tip
The Registry can become fragmented
just like any other file can. There are Registry defraggers as well as
optimization tools that remove unused Registry keys (uninstalled
programs are supposed to remove their keys, but many don’t). But I don’t
find that these programs make any discernible difference in
performance.
