System Restore Function

System Restore is a function that was introduced in Windows XP. It enables you to roll back system settings (e.g., system files, registry entries, installed software) to an earlier state if the current configuration in not functioning properly, returns errors or fails. However, if your system was damaged it is unlikely that System Restore will work.

System Restore function is an option to consider while fixing 0xC0000005 problems. The advantages of System Restore method are:

  • the possibility to undo the changes
  • the possibility to rollback to different timepoints

System Restore backs up .exe, .dll and other system files, as well as the registry and drivers, so that later they can be retrieved and used to restore the old configuration. However, the roll back period is limited to several weeks because system backups are kept within the allocated disk space. Windows XP requires the 200Mb minimum disk space, otherwise it will be automatically disabled.

Backups are created automatically or at user's request. Automatic backups and corresponding restore points are scheduled in the following way:

  • Every 24 hours, both when the computer is on or off. If the computer is off for over 24 hours, the system checkpoint is created at startup. This setting is configurable.
  • At the installation of Windows updates through Windows Update, new programs by using System Restore aware installers or the Windows Installer, or drivers that are not digitally signed by Windows Hardware Quality Labs,

When Should I Use System Restore?

Do it only after trying less critical methods, such as restarting, Last Known Good Configuration, and registry repair because System Restore may affect and replace more files than you would like to.

How to Use System Restore in Windows

You are recommended to close all programs before applying System Restore.

  1. Click Start => All Programs => Accessories => System Tools => System Restore.
  2. In the Welcome to System Restore window, choose "Restore my computer to an earlier time", and click Next.
  3. Now you see the restore calendar on the Select a Restore Point screen. Restore points are marked in bold. Choose the date that precedes the date when the problem occurred (sometimes you may choose an earlier time point on the same day). Try to choose the closest Restore Point to the time when the problem appeared, then click next.

System Restore

  1. Confirm your choice on the Confirm Restore Point Selection by clicking Next.
  2. The computer will restore the system settings and reboot. When you are displayed the Restoration Complete screen, click OK. An additional Undo restore point will be created, enabling you to restore the settings you started from.

If you are not able to start System Restore in Normal Mode, you can do it in Safe Mode. But remember, in this case you won't be able to undo these changes!

Basic Error Concepts: