When to use the ERD, Safe Mode, and the Recovery Console
In Windows 2000, everything is bigger and more sophisticated than in Windows NT, including the native troubleshooting and repair tools. When something goes wrong with the OS, you have three options: You can use your Emergency Repair Disk (ERD) to initiate a repair operation; you can boot to Safe Mode to avoid troublesome drivers or application-specific problems; or, as a last resort, you can boot to the Recovery Console (RC) and disable a malfunctioning driver or service. All three of these tools can help you diagnose or recover from system problems that are the result of missing or corrupted files, a confused driver, or a temporary pagefile that won't go away. To determine which tool to use in a given set of circumstances, you need to understand the scope of the troubleshooting and repair operations that the ERD, Safe Mode, and the RC offer.
ERD Repairs
If you have a system that simply won't boot, you need the ERD. You can use the ERD to repair a damaged boot sector, repair a damaged Master Boot Record (MBR), repair or replace missing or damaged NT Loader (NTLDR) and ntdetect.com files, and reload a third-party ntbootdd.sys SCSI driver that you need to access the boot drive. The ERD lets you recover the system disk after a virus infection and is the only tool that lets you boot a system from the shadow of a broken mirror set.
One result of Win2K's bigger and better approach to repair tools is the larger size of the configuration databases—commonly called SYSTEM hives—that Win2K stores in the registry. Win2K's larger and more numerous hive files no longer fit on an ERD. Therefore, Microsoft has trimmed down Win2K's ERD utility so that it provides only three functions:
- inspect and repair the startup environment
- verify Win2K files and replace missing or damaged files
- inspect and repair the boot sector
If your repair needs go beyond such minor corrections—for example, if incorrect or damaged device drivers are installed in the System folder or if problems occur after you see the startup (OSloader) screen—you need to use either Safe Mode or the RC.
Creating a Current ERD
Creating an ERD as you deploy each system in your enterprise should be standard procedure. In some cases, the ERD is the only utility you can use to get a system up and running again. Creating an ERD not only gives you the benefit of quick access to an essential repair tool—it's also easier than ensuring that each workstation has a copy of the distribution media or has access to a network-based installation share point. Additionally, the ERD is the fastest way to create an on-disk backup copy of active registry databases—you can repair a system much faster if you have an on-disk copy as opposed to a copy on backup media.
Win2K setup disks contain a version of the ERD. This version is useful only when you're initially installing a system. After you customize the OS (e.g., enable or disable services, add individual and group accounts, add security information), the generic ERD is too outdated to help you recover a system. To ensure that you'll be able to recover a certain system in the event of a failure, you must create a new ERD after you configure the system to your satisfaction.
To create an ERD that can back up your current system configuration, use Win2K's Backup utility. Backup doesn't appear in Administrative Tools (where you might expect it) but rather is tucked away under System Tools in the Accessories program group. You can also start the Backup utility by opening a command prompt and typing
ntbackup
In either case, Backup starts by displaying the Welcome tab. When you select the Create an Emergency Repair Disk option on this tab, Backup prompts you to place a blank formatted disk in the 3.5" floppy disk drive, as Figure 1 shows.