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Restoring and Recovering System Files

Sometimes the operating system and its applications can become unstable and not function correctly due to errors in system files or configuration. This is often caused by installing buggy software (including operating system updates) or user error. In this section, we compare how Mac OS X and Windows XP fix these types of issues by restoring or "rolling back" to a previous, more stable, state of the operating system.

Not to be confused with Backing Up and Restoring Files, which compares the backup abilities of all the files for a user in case of data loss or corruption. This section discusses Mac OS X and Windows XP ability to revert to previous versions of their system files or configuration.

Mac OS X:

As we mentioned in our Backing Up and Restoring Files comparison, OS X has no built-in backup software. Your only method is to use Disk Utility's restore feature to create a disk image of the entire contents of your boot volume (including personal files and applications) to restore at a later period in case of problems.

Roll back in OS X? One reader's experience...

"You noted that OS X does not have a 'roll back' feature. However, it does have a close approximation - the Archive and Install function on the OS X Install CDs.

I don't know if you ever had the unfortunate need to use this feature, so I will take the liberty of describing it for you. I had need to use it after I encountered persistent printing glitches that it seemed that no amount of tweaking would fix. As a last resort, I decided to reinstall the operating system and start from scratch. By booting from the OS X install CDs (not the Software Restore Disks), selecting "Archive and Install," and selecting "Preserve Users and Settings" (this may not be the exact dialog wording), I was able to do this in about 30 minutes. The installer replaces your /System and /Library folders, among others, and files the old copies of those folders into "/Previous System". At the same time, the installer recreates the users and maintains the copies of your Home directory, including preference files. The net result was that 30 minutes after starting the reinstall, I rebooted and logged back in using my old user name and password, with all of my settings (and many of my modifications to the system - extra preference panes in ~/Library, for example) intact. The installer preserved any modification that wasn't made at the OS level - down to my customization of the Finder toolbars and my exact configuration of the Dock. Even the UNIX packages I had installed through Fink were preserved. Furthermore, the few system level extensions I had installed could either be copied out of the "/Previous System" folder or freshly reinstalled.

Now, this does not seem to be exactly the same as XP's "System Restore" feature. Before reinstalling, I had 10.2.3 installed, afterwards, I had 10.2. However, since the need to reinstall a system may have been introduced by a minor system update, this seems like a reasonable solution. In my case, it was a quick run of Software Update to go to 10.2.3, followed by a few quick installs of some system-level haxies. All in all, it took me 1.5 - 2 hours to exactly restore the system to its previous state (minus print glitches), during most of which I did nothing but waited on the installer and my network connection. I would say that this is a fairly painless procedure, considering that it involves swapping out the entire core of the operating system."

Regards,
Z.H.

Windows XP:

XP comes with a utility called System Restore located at Start Menu > All Programs > Accessories > System Tools. System Restore automatically creates a "restore point" when it detects modifications to system files or configuration. Users can also create restore points manually if they wish. You can later revert to a restore point if XP has become unstable or is experiencing lots of errors. All restore points are reversible.

XP's System Restore

Restore points are organized in a calendar-style layout. Users can choose to revert their system from any restore point that has been previously created.

System Restore doesn't replace any of the files located in the My Documents folder or those with common data file types such as Word documents or Excel spreadsheets. Microsoft recommends placing all files you don't wish to overwrite in the My Documents folder to be safe.

The support article Frequently Asked Questions Regarding System Restore in Windows XP from Microsoft's website goes into further details as to what is exactly restored by System Restore.

Note: Applications installed after a restore point may not function correctly when rolled back to that restore point. The application .exe may still exist, but some of its configuration files may not.

Conclusion

While Z.H.'s experience with the 'Archive and Install' option on the OS X install disks illustrates how easy it is to re-install the core operating system while preserving a user's files and setting, it still doesn't compare to XP's System Restore feature. System Restore offers users a more flexible, hassle-free way of repairing the operating system without having to re-install the operating system. A few clicks and the operating system has been reverted to a previous state.

OS X:

• 'Archive and Install' offers OS X users the ability to reinstall the entire operating system while preserving personal files and settings
• Can't schedule or manually create "restore points" to revert system files and configuration back to in case of problems

XP:

• System Restore allows XP users to create "restore points" of their system files and configuration to revert to in case of problems

Mac OS X: 6
Windows XP: 9