Backing Up the Registry
Windows Vista maintains what is known as the system state: the crucial
system files that Windows Vista requires to operate properly. Included
in the system state are the files used during system startup, the
Windows Vista–protected system files, and, naturally, the Registry
files. Windows Vista’s Backup utility has a feature called Complete PC
Backup that enables you to easily back up the current system state, so
it’s probably the most straightforward way to create a backup copy of
the Registry should anything go wrong.
Saving the Current Registry State with System Restore
Another easy way to
save the current Registry configuration is to use Windows Vista’s System
Restore utility. This program takes a snapshot of your system’s current
state, including the Registry. If anything should go wrong with your
system, the program enables you to restore a previous configuration.
It’s a good idea to set a system restore point before doing any work on
the Registry.
Tip
Another way to protect
the Registry is to ensure that its keys have the appropriate
permissions. By default, Windows Vista gives members of the
Administrators group full control over the Registry. A Standard user
gets Full Control permission only over the HKCU key when that user is logged on and Read permissions over the rest of the Registry. To adjust the
permissions, right-click the key in the Registry Editor, and then click
Permissions. Make sure that only administrators have the Full Control
check box activated.
Protecting Keys by Exporting Them to Disk
If you’re just making a
small change to the Registry, backing up all of its files might seem
like overkill. Another approach is to back up only the part of the
Registry that you’re working on. For example, if you’re about to make
changes within the HKEY_CURRENT_USER key, you could back up just that key, or even a subkey within HKCU. You do that by exporting the key’s data to a registration file, which is a text file that uses the .reg extension. That way, if the change causes a problem, you can import the .reg file back into the Registry to restore things the way they were.
Exporting the Entire Registry to a .reg File
The easiest way to protect the entire Registry is to export the whole thing to a .reg
file on a separate hard drive or network share. Note that the resulting
file will be 90 to 100 MB, and possible larger, so make sure the target
destination has enough free space. Here are the steps to follow:
1. | Open the Registry Editor.
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2. | Select File, Export to display the Export Registry File dialog box.
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3. | Select a location for the file.
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4. | Use the File Name text box to type a name for the file.
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5. | Activate the All option.
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6. | If
you’ll be importing this file into a system running Windows 9x, Windows
Me, or Windows NT, use the Save As Type list to choose the Win9x/NT 4
Registration Files (*.reg) item.
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7. | Click Save.
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Exporting a Key to a .reg File
Here are the steps to follow to export a key to a registration file:
1. | Open the Registry Editor and select the key you want to export.
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2. | Select File, Export to display the Export Registry File dialog box.
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3. | Select a location for the file.
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4. | Use the File Name text box to type a name for the file.
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5. | Activate the Selected Branch option.
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6. | If
you’ll be importing this file into a system running Windows 9x, Windows
Me, or Windows NT, use the Save As Type list to choose the Win9x/NT 4
Registration Files (*.reg) item.
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7. | Click Save.
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One common Registry
scenario is to make a change to Windows Vista using a tool such as the
Group Policy editor, and then try and find which Registry setting (if
any) was affected by the change. However, because of the sheer size of
the Registry, this is usually a needle-in-a-haystack exercise that ends
in frustration. One way around this is to export some or all the
Registry before making the change and then export the same key or keys
after making the change. You can then use the FC (file compare) utility
at the command prompt to find out where the two files differ. Here’s the
FC syntax to use for this:
FC /U pre_edit.reg post-edit.reg > reg_changes.txt
Here, change pre_edit.reg to the name of the registration file you exported before editing the Registry; change post_edit.reg to the name of the registration file you exported after editing the Registry; and change reg_changes.txt to the name of a text file to which the FC output is redirected. Note that the /U switch is required since registration files use the Unicode character set.
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Importing a .reg File
If you need to restore the key that you backed up to a registration file, follow these steps:
1. | Open the Registry Editor.
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2. | Select File, Import to display the Import Registry File dialog box.
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3. | Find and select the file you want to import.
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4. | Click Open.
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5. | When Windows Vista tells you the information has been entered into the Registry, click OK.
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Note
You also can import a .reg file by locating it in Windows Explorer and then double-clicking the file.
Caution
Many applications ship with their own .reg
files for updating the Registry. Unless you’re sure that you want to
import these files, avoid double-clicking them. They might end up
overwriting existing settings and causing problems with your system.
