Making Sure the System Always Starts

This section discusses:

• Starting a system with configuration problems

• Reconstructing a system with damaged files

• Creating a custom startup verification program

The goal in all of these situations is to make sure a Windows NT system starts correctly each time you turn on the switch. Of course, you need to plan ahead for system safety by doing the following:

• Maintain a regular backup program, including backups of Registry hives, as described in "Maintaining the Registry" in Chapter 24, "Registry Editors and Registry Administration."

• Maintain a copy of the Emergency Repair Disk created when you installed Windows NT. Each Emergency Repair Disk works only for the computer where it was made. Use Repair Disk Utility (Rdisk), a tool installed with Windows NT, to update the Emergency Repair Disk with the current version of Registry hives. For more information, see Help for the Repair Disk Utility.

• Install a redundant copy of the operating system to make the system more robust, as described in Chapter 2, "Customizing Setup."

You can also rely on Windows NT to automatically recover from damages to startup data. Specifically, to protect the system from corrupted sectors in the System hive, Windows NT automatically creates a backup of the System hive—the System.alt file—which is stored in Systemroot\System32\Config. If any problems are encountered while reading the System hive during startup, such as damage to the file, the Boot Loader automatically switches to the System.alt file to continue startup. For more information about the System.alt file, see "Hives and Files" in Chapter 23, "Overview of the Windows NT Registry."