Because the Registry is now the one
place where all the Windows hardware and software settings are stored,
it’s also the one thing that Windows absolutely needs to run. If you
have to use the Registry Editor to manually change Registry settings, we
strongly suggest that you back up your Registry before you make any changes.
Backing Up the Registry
You
can back up the Registry several ways. In order of preference, these
are using a third-party Registry-backup program, backing up the entire
hard disk using a third-party program or Complete PC Backup, using
System Restore, and using the Registry Editor to save a key to a text
file.
I suggest that you use a third-party disk-backup
solution to back up the Registry files every time you back up your hard
disk. Before you install a piece of new hardware or a significant
software package, do a full disk backup, including the Registry. Before
you manually edit the Registry for other purposes, back up the Registry
by any of the means discussed in the next few sections.
Backing Up with Third-Party Registry-Backup Software
There are third-party programs specifically
designed to back up and restore the Registry. For example, SuperWin’s
WinRescue program (www.superwin.com)
not only can back up and restore the Registry, but also can defragment
the Registry’s files and work magic to revive a nonbootable Windows
system. (There is a version called WinRescue Vista that you should use
if no Windows 7–specific version has been released.) There is also a
free tool called ERUNT, which you can download from www.larshederer.homepage.t-online.de/erunt.
These programs come with instructions on backing up, restoring, repairing, and maintaining the Registry.
Backing Up the Hard Disk
You can save the Registry by performing a
backup of the entire contents of the hard disk on which Windows resides.
On the Windows 7 Home versions, you’ll have to use a third-party disk
backup program to back up the entire hard disk. On Windows 7
Professional, Enterprise, and Ultimate editions, the Complete PC Backup
program can do this for you, or you can use a third-party program.
Caution
The backup programs
provided with Windows 7 do not provide a good means of backing up the
Registry as insurance against accidents. Windows Backup can perform only full-volume backups, which can take a long time. System Restore backs up only HKEY_LOCAL_MACHINE, not your own HKEY_CURRENT_USER data. It’s okay to use only if you’re modifying just HKEY_LOCAL_MACHINE settings. |
As an alternative to doing a full disk backup,
most third-party disk-backup programs made for Windows 7 include an
option to back up the system portion of the Registry. If you use this
option, be sure to include all user profiles (everything under \User) so that personal Registry sections are saved as well.
Check your backup software’s manual for
instructions on saving Registry and system information when you back up.
I suggest that you always include the Registry in your backups.
Backing Up with System Restore
If you will be changing only entries under HKEY_LOCAL_MACHINE, you can create a restore point to back up a copy of this part of the Registry. To create a restore point, follow these steps:
1. | Click Start. Right-click Computer and select Properties. Then, at the left, select System Protection. (Alternatively, type sysdm.cpl in a Command Prompt window, and then select the System Protection tab.)
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2. | Be sure that the disk volume that contains Windows is checked, and click Create.
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3. | Enter a description for the restore point, such as Before changing Registry, and then click Create.
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Backing Up with the Registry Editor
The Registry Editor has a mechanism to export a
set of Registry keys and values to a text file. If you can’t or won’t
use a more comprehensive backup system before you manually edit the
Registry, at least use this editor to select and back up the key that
contains all the subkeys and values you plan to modify. Remember,
though, that Regedit cannot remove entries you added that were not in
the Registry before the backup!
To back up a key and its subkeys and values, follow these steps:
1. | To run Regedit, click Start, and type regedit in the Search box.
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2. | When Regedit appears under Programs in the search results, select it and press Enter. (Alternatively, type regedit in a Command Prompt window.)
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3. | Locate and select the key you plan to modify, or a key containing all the keys you plan to modify, in the left pane.
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4. | Select File, Export.
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5. | Choose
a location and filename to use to store the Registry keys. I usually
use the desktop for temporary files like this, so that I’ll see them and
delete them later.
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6. | Select All Files from the Save As Type list, and enter a name (possibly with an extension other than .reg—for example, before.sav).
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7. | Click Save. The chosen key or keys are then saved as a text file.
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Restoring the Registry
If you’ve made Registry changes that cause
problems, you can try to remember each and every change you made,
re-enter the original information, delete any keys you added, and thus
undo the changes manually. Good luck! If you were diligent and made a
backup before you started, however, you can simply restore the backup
and have confidence that the recovery is complete and accurate.
Registry
corruption can take two forms: Either the Registry’s database files can
be damaged by an errant disk operation, or information can be mangled
by a buggy program or an overzealous regedit user. No matter what the cause, the result can be a system that won’t run or one that reboots itself over and over. These could be other signs of Registry corruption or errors: Drivers aren’t loaded, or they give errors while Windows is booting. Software complains about components that aren’t registered or cannot be located. Undesirable programs attempt to run when you log in. Windows does not boot, or it starts up only in Safe mode.
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If you made a Registry backup using a
third-party disk or Registry backup tool, use the instructions that came
with your product to restore the Registry. If you created a restore
point or used Regedit, follow the steps described in the following
sections.
Restoring the Registry from a Restore Point
If you created a restore point before modifying the Registry, you can back out the change by following these steps:
1. | Click
Start. Right-click Computer and select Properties. At the left, select
System Protection. Then, click the System Restore button.
(Alternatively, type rstrui in a Command Prompt window.)
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2. | Locate the restore point you created. Select it and click Next; then click Finish. Windows will restart.
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If the Registry problem is severe enough that
Windows can’t boot or get to the System Restore function, you can
perform a system restore from the system recovery tools on your Windows
setup DVD.
Restoring the Registry from Regedit
If a Registry editing session has gone awry and
you need to restore the Registry from a key you saved from within
Regedit, follow these steps:
1. | In Regedit, select File, Import.
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2. | Select All Files from the Files of Type list.
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3. | Locate the file you used to back up the Registry key or keys—for example, before.reg.
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4. | Select Open.
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The
saved Registry keys are then imported, replacing any changes or
deletions. However, any keys or values you’ve added to the Registry are
not removed. If they are the cause of the problem, this restore will not help.
Tip
If you encounter what
you think are Registry problems with add-on software, your best bet is
to uninstall the software, if possible, and reinstall it before
attempting any Registry restores or repairs. |
If the Registry problems persist, you
can try a rather drastic measure: You can use Regedit to delete the key
or keys that were changed and then import the backup file again. This
time, any added keys or values are removed. I suggest that you try this
approach only with keys related to add-on software, not for any of the Microsoft software or hardware keys.
