Working with Registry Keys and Settings

Now that you've had a look around, you're ready to start working with the Registry's keys and settings. In this section, I'll give you the general procedures for basic tasks, such as modifying, adding, renaming, deleting, and searching for entries, and more.

Changing the Value of a Registry Entry

Changing the value of a Registry entry is a matter of finding the appropriate key, displaying the setting you want to change, and editing the setting's value. Unfortunately, finding the key you need isn't always a simple matter. Knowing the root keys and their main subkeys, as described earlier, will certainly help, and the Registry Editor also has a Find feature that's invaluable (I'll show you how to use it later).

To illustrate how this process works, let's work through an example: changing your Windows XP registered owner name and company name. During the Windows XP installation process, Setup may have asked you to enter your name and, optionally, your company name. (If you upgraded to Windows XP, this data was brought over from your previous version of Windows.) These "registered names" appear in several places as you work with Windows XP:

• If you open the Control Panel's System icon, your registered names appear in the General tab of the System Properties dialog box.

• If you select Help, About in most Windows XP programs, your registered names appear in the About dialog box.

• If you install a 32-bit application (including Office), the installation program uses your registered names for its own records (although you usually get a chance to make changes).

With these names appearing in so many places, it's good to know that you can change either or both names (for example, if you give the computer to another person). The secret lies in the following key:

HKLM\SOFTWARE\Microsoft\WindowsNT\CurrentVersion

To get to this key, open the branches in the Registry Editor's tree pane: HKEY_LOCAL_MACHINE, SOFTWARE, Microsoft, and then WindowsNT. Finally, click the CurrentVersion subkey to highlight it. Here you'll see a number of settings, but two are of interest to us:

Saving Favorite Keys

If you have keys that you visit often, you can save them as "favorites" to avoid trudging through endless branches in the Keys pane. To do this, navigate to the key and then select Favorites, Add to Favorites. In the Add to Favorites dialog box, edit the Favorite Name text box, if necessary, and then click OK. To navigate to a favorite key, pull down the Favorites menu and select the key name from the list that appears at the bottom of the menu.

• RegisteredOrganizationThis setting contains the registered company name.

• RegisteredOwnerThis setting contains your registered name.

Now you open the setting for editing by using any of the following techniques:

• Highlight the setting name and either select Edit, Modify or press Enter.

• Double-click the setting name.

• Right-click the setting name and click Modify from the shortcut menu.

The dialog box that appears depends on the value type you're dealing with, as discussed in the next few sections. Note that edited settings are written to the Registry right away, but the changes might not go into effect immediately. In many cases, you need to exit the Registry Editor and then either log off or restart Windows XP.

Editing a String Value

If the setting is a REG_SZ value (as it is in our example), a REG_MULTI_SZ value, or a REG_EXPAND_SZ value, you see the Edit String dialog box, shown in Figure A.4. Use the Value Data text box to enter a new string or modify the existing string, and then click OK. (For a REG_MULTI_SZ multi-string value, Value Data is a multiline text box. Type each string value on its own line. That is, after each string, press Enter to start a new line.)

Figure A.4. You use the Edit String dialog box to modify a string value.

Editing a DWORD Value

If the setting is a REG_DWORD value, you see the Edit DWORD Value dialog box shown in Figure A.5. In the Base group, select either Hexadecimal or Decimal, and then use the Value Data text box to enter the new value of the setting. (If you chose the Hexadecimal option, enter a hexadecimal value; if you chose Decimal, enter a decimal value.)

Figure A.5. You use the Edit DWORD Value dialog box to modify a DWORD value.

Editing a Binary Value

If the setting is a REG_BINARY value, you see an Edit Binary Value dialog box like the one shown in Figure A.6.

Figure A.6. You use the Edit Binary Value dialog box if you're modifying a binary value.

For binary values, the Value Data box is divided into three vertical sections:

• Starting byte numberThe four-digit values on the left of the Value Data box tell you the sequence number of the first byte in each row of hexadecimal numbers. This sequence always begins at 0, so the sequence number of the first byte in the first row is 0000. There are 8 bytes in each row, so the sequence number of the first byte in the second row is 0008, and so on. These values can't be edited.

• Hexadecimal numbers (bytes)The eight columns of two-digit numbers in the middle section display the setting's value, expressed in hexadecimal numbers, where each two-digit number represents a single byte of information. These values are editable, but because of the obvious complexities involved with hexadecimal numbers, few computer users take advantage of this "feature."

• ASCII equivalentsThe third section on the right side of the Value Data box shows the ASCII equivalents of the hexadecimal numbers in the middle section. In Figure A.6, for example, the first byte of the second row is the hexadecimal value 35, which represents the number 5. The values in this column are also editable.

Renaming a Key or Setting

You won't often need to rename existing keys or settings. Just in case, though, here are the steps to follow:

1.	In the Registry Editor, find the key or setting you want to work with, and then highlight it.
2.	Select Edit, Rename, or press F2.
3.	Edit the name and then press Enter.

Rename with Care

Rename only those keys or settings that you created yourself. If you rename any other key or setting, Windows XP might not work properly.

Creating a New Key or Setting

Many Registry-based customizations don't involve editing an existing setting or key. Instead, you have to create a new setting or key. Here's how you do it:

1.	In the Registry Editor, highlight the key in which you want to create the new subkey or setting.
2.	Select Edit, New. (Alternatively, right-click an empty section of the Settings pane and then click New.) A submenu appears.
3.	If you're creating a new key, select the Key command. Otherwise, select the command that corresponds to the type of setting you want: String Value, Binary Value, DWORD Value, Multi-String Value, or Expandable String Value.
4.	Type a name for the new key or setting.
5.	Press Enter.

For example, Office versions prior to 2003 have a feature called AutoSelect that automatically selects the first available document when you display the Open dialog box. If that was the document you wanted, you only had to press Enter to open it. This was an occasionally handy feature that Microsoft disabled in Office 2003 because AutoSelect would sometimes cause long delays when displaying a network folder. Fortunately, you can tweak the Registry to enable AutoSelect again. First, head for the following key:

 HKEY_CURRENT_USER\Software\Microsoft\Office\11.0\Common\Open Find 

Add a new DWORD value named DisableAutoSelect and set its value to 0.

Deleting a Key or Setting

Follow these steps to delete a key or setting:

1.	In the Registry Editor, highlight the key or setting that you want to delete.
2.	Select Edit, Delete, or press Delete. The Registry Editor asks if you're sure.
3.	Click Yes.

Delete with Care, Too

Again, to avoid problems you should delete only those keys or settings that you created yourself. If you're not sure about deleting a setting, try renaming, instead. If a problem arises, you can also return the setting back to its original name.