Windows XP

Windows XP Registry File Structure and Locations

In Windows XP, the registry is saved in separate files in the windows directory. The Windows XP registry files are located in the %systemroot%/system32/config directory* . Within the Windows XP registry files are the structure of the hives and corresponding location of each hive. This article will help you understand how the Windows XP registry files correspond with the hierarchial structure.

* (%systemroot% is usually WINDOWS or WINNT)

In the registry, there are hives that correspond to several files. Hives are a collection of keys, subkeys and values that contain the configurations for the operating system and programs. In the registry, there are 5 groups:

HKEY_CLASSES_ROOT - (HKCR),
HKEY_CURRENT_USER - (HKCU),
HKEY_LOCAL_MACHINE - (HKLM),
HKEY_USERS - (HKU),
HKEY_CURRENT_CONFIG - (HKCC).

For the corresponding hives, you will see several types of extensions: no extension, .alt, .log, and .sav.

No Extension: The complete registry hive
.alt: An alternate copy of the registry hive
.log: A log of changes that have occurred within the registry hive
.sav: This is an automatic backup created from when a setup or program installation occurs.

Here are the corresponding files:

HKCC: System, System.alt, System.log, System.sav
HKCU: Ntuser.dat, Ntuser.dat.log
HKLMSAM: Sam, Sam.log, Sam.sav
HKLMSecurity: Security, Security.log, Security.sav
HKLMSoftware: Software, Software.log, Software.sav
HKLMSystem: System, System.alt, System.log, System.sav
HKU.DEFAULT: Default, Default.log, Default.sav

Another thing to mention is that there is a "repair" copy just in case your registry gets corrupted. These files are located in the %systemroot%/repair directory. These usually will come in handy when you get bootup errors and need a find a clean copy of the registry. One way to fix this problem is to use the Windows CD to get into the recovery console. From there, you would be able to copy the registry files from the "repair" folder to the system32/config directory.

So you can see the logic behind the registry editor with the structure and location of the Windows XP registry files. By knowing this information, you can understand how a registry works with the operating system. These files can get corrupted just like any other files and knowing where they are located can help in troubleshooting many issues in the future. The Windows XP registry files are very delicate to work with, so make sure that you are taking absolute care when manipulating these files.

Brad Carter is a computer consultant junkie that loves to dive into the technicalities of PC optimization. He runs a blog that provides free tips, reviews, and solutions on topics of registry repair. To learn more about registry fixers and PC performance, run over to Brad's blog at http://windowsxpregistryrepair.blogspot.com

Article Source: http://EzineArticles.com/?expert=Brad_Carter

To Remotely Edit the Registry
  1. Start computer with Bart PE,
  2. Start Regedit - go to key HKLM, Load Hive "C:\WINDOWS\system32\config\software" (assign name - e.g. "temp") (example used is "software", see names above for desired hive)
  3. Make edits desired, Unload hive, close regedit.

Create and Restore System Restore Points Manually

Only application installations that use a System Restore restorept.api-compliant installer will trigger the creation of a restore point. So it's a good idea to create a restore point manually before you install an application that you suspect won't have one a restorept.api-compliant installer. For example, before installing a screensaver you've downloaded from the Internet or a beta program from a software vendor, you should manually create a restore point. For more information, see the TechNet article, http://support.microsoft.com/kb/310405 .

To manually create a restore point:

  1. Click Start, point to All Programs, point to Accessories, point to System Tools, and then click System Restore.
  2. On the Welcome page, click Create a restore point.
  3. On the Create a Restore Point page, enter a descriptive name for your restore point, as shown in Figure 3, and then click Create
  4. The Restore Point Created page confirms that the new restore point has been created. I think it's a good idea to manually create a restore point before you download and install any application from the Internet.

To manually use System Restore to restore Windows XP to a previous state:

  1. Log on to Windows as Administrator.
  2. Click Start, point to All Programs, point to Accessories, point to System Tools, and then click System Restore. System Restore starts.
  3. On the Welcome to System Restore page, click Restore my computer to an earlier time (if it is not already selected), and then click Next.
  4. On the Select a Restore Point page, click the most recent system restore point in the On this list, click a restore point list, and then click Next.
    Note A System Restore message may appear that lists configuration changes that System Restore will make. Click OK.
  5. On the Confirm Restore Point Selection page, click Next. System Restore restores the previous Windows XP configuration, and then restarts the computer.
  6. Log on to the computer as Administrator. The System Restore Restoration Complete page is displayed.
  7. Click OK.

If you successfully restored your computer to a previous state, and the computer is performing as it should be, you are finished.

Article ID : 322756
Last Review : November 20, 2007
Revision : 7.5
From: http://support.microsoft.com/kb/322756

Manual steps to back up the registry in Windows XP

1. Click Start, click Run, type %SystemRoot%\system32\restore\rstrui.exe, and then click OK.
2. On the Welcome to System Restore page, click Create a restore point, and then click Next .
3. On the Create a Restore Point page, type a name for the restore point and then click Create
4. After the restore point has been created, click Close.

Note If System Restore is turned off, you receive a message that asks whether you want to turn on System Restore now. Click Yes. Then, in the System Properties dialog box, click to clear the Turn off System Restore check box, click OK, and then repeat this step.

Manual steps to restore the registry in Windows Vista or Windows XP

Use System Restore to undo registry changes in Windows XP

1. Click Start, click Run, type %SystemRoot%\System32\Restore\Rstrui.exe, and then click OK.
2. On the Welcome to System Restore page, click Restore my computer to an earlier time (if it is not already selected), and then click Next .
3. On the Select a Restore Point page, click the system checkpoint. In the On this list select the restore point area, click an entry that is named "Guided Help (Registry Backup)," and then click Next. If a System Restore message appears that lists configuration changes that System Restore will make, click OK.
4. On the Confirm Restore Point Selection page, click Next. System Restore restores the previous Windows XP configuration and then restarts the computer.
5. Log on to the computer. When the System Restore confirmation page appears, click OK..