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

8.2. Adding and Deleting Registry Keys and Values

The Registry Editor, as mentioned
earlier, is the primary tool for viewing, modifying, and deleting
data in the Registry. And as you'll see later in
this chapter, it also allows you to conveniently import and export
data (via Registry patches), which can be thought of as another form
of data entry.

Basic data entry in Registry Editor is fairly simple. In order to
type data, you must first create a value to hold it. Depending on
your goal, you may also need to create a new key in which to place
the value.

To create a new key or value, use Edit
New. The key or value
then appears within the currently selected key, with the name New Key
or New Value #1, respectively. A new string value will have the null
string as its value; a new binary value will show the following
message in parentheses: "(zero length binary
value)." A new DWORD value will show up as zero:
0x00000000 (0). You can then
edit that value (see later in this chapter) to change it. New keys
aren't created empty, either. They all contain the
(Default) value described in the previous section.

To delete a key or value, select it
and click Edit Delete, or
simply press the Del key. But be warned,
there's no undelete, so you might want to first
write out the branch containing the key you're about
to delete as a .reg file (see Section 8.5 and Section 8.6, later in this chapter). Or,
you can use Edit Rename
to rename the value or key. Since applications access values and keys
by their names, renaming has the effect of disabling or
"hiding" the item from the
application that uses it, while preserving its data.

To edit a value, double-click on its
icon or name, or highlight it and use Edit
Modify. You will see an
edit box appropriate to the value type. When editing a string value,
Registry Editor provides a standard text box, in which you can type
text, as well as copy and paste (by right-clicking on the text, or by
using Ctrl-C, Ctrl-X, and Ctrl-V). Binary values have a more
complicated and less familiar edit dialog, which allows data entry
via ASCII codes on the left, or plain text on the right. Finally,
DWORD values have a simpler edit interface, providing only for entry
of a single number (either in Hex or Decimal format). Cut, Copy, and
Paste work in DWORD and Binary dialogs as well. See the previous
section, Section 8.1, for more
details on the different types of values.

Unfortunately, automation in Registry Editor is virtually
nonexistent. For example, you can't copy and paste
whole keys or values like you might expect (given the familiar
Explorer-like interface), but you can copy key and value

names to the clipboard by pretending
you're going to rename them, and then pressing
Ctrl-C to copy. Another useful tool is the Copy Key Name command on
the Edit menu, which copies the full path to the selected key to the
Clipboard (very handy for writing this book, for example). It
doesn't copy the contents of the key, nor does it
include the selected value, however.

If you want to duplicate an existing value, double-click it and
select all of the data in the Edit window (see Figure 8-4).

Figure 8-5. Copying an existing Registry value

Ctrl-C will copy the data to the clipboard. Then create a new value,
being sure to match the type (string, binary, or DWORD) of the
original value. Type the desired value name, double-click the new
value to edit it, and then use Ctrl-V to paste the copied data into
the edit window.

Duplicating values can be handy not only when using an existing value
as a template for a new value, but also whenever
you're going to make changes to an existing value.
You can make little "inline
backups" by creating a new value
(whatever.bak, for
instance) and pasting in the old value data before you change it.
This might seem a little tedious, but it might prevent future
headaches if you're about to change a complex value
whose format you aren't completely sure you
understand, or even if you anticipate having to roll back a value to
its previous state for some reason.

Unfortunately, there's no easy way to copy a key and
all of its contents in Registry Editor. If you want to copy an entire
key and all its values, you'll have to do it one
value at a time. It's usually much easier to export
the key, edit the resulting file with a text editor, and then import
the edited file. (See Section 8.6
later in this chapter.)

In addition to the Edit menu, you may find Registry
Editor's context menus convenient. Right-clicking
on a key in the left pane gives a context menu with Expand or
Collapse, New, Find, Delete, Rename, and Copy Key Name. (Expand
displays a key's subkeys. It will be grayed out if
there are no subkeys to display, and it will be replaced with
Collapse if said subkeys are already showing.) Right-clicking with a
value selected in the right pane gives a context menu with Modify,
Delete, and Rename. Right-clicking in the right pane with no value
selected gives a context menu with New (to create a new string,
binary, or DWORD value). Press Shift-F10 to open a context menu
without having to use the mouse.