Recovering from Disaster, or Making the Best of a Bad Situation

Overview

Disaster usually strikes when least expected. There it is, usually late at night, just when things are sailing smoothly along, and whammo! A server fails, maybe with an infamous "blue screen of death." (When a system error occurs in Windows that is so severe that the operating system cannot continue, it displays a blue screen with white characters telling you about the error.)

Disaster can also strike when Windows XP boots. Maybe the system starts fine, then mysteriously crashes in any of a thousand ways after a few minutes, a few hours, or even a few days. On the other hand, maybe, just maybe, out of the blue something happens and the system becomes unstable.

In this chapter, we'll look at how to survive when disaster strikes. Rather than panic, I'll show you how to systematically discover the problem and get your system up and running again.

When Failure Strikes

One server on my network used to crash on a regular basis. It was easy to blame the operating system or applications. I never could figure out exactly why it crashed, but I do know that when I upgraded the system with a new CPU, motherboard, and memory, those mysterious system crashes became a thing of the past. It is now common for the server to run for weeks without a single problem.

Note "Bad" memory is probably the single most common problem with computers. Memory failures can (and do) masquerade as many different faults, and they can be very difficult to troubleshoot. Consider using the best memory available and keeping spare memory on hand to swap into an unreliable computer.

Sometimes you have to figure out what happened. Maybe a hardware problem precipitated the failure. Or perhaps a failing hard drive with a bad sector in an infrequently used section of a system file caused the problem. Maybe, and this one is nasty, there's a bad spot in the registry.

When disaster strikes, a methodical approach to recovery is the only reasonable path to follow. You can try the shotgun technique: replace things randomly until something fixes the problem. Or you can use a more logical technique: analyze the problem and apply fixes in a systematic method. I vote for the latter; I've tried shotgun type repairs, and they are so

difficult to do that in the end, only the most inexperienced user will try to fix a problem using such a random technique.

Warning Have I already said this? Back up your registry before doing anything described in this chapter. Manually removing items from a registry is perhaps the easiest way to trash everything! Back up, back up, and back up again.

Note Remember to check the Event Viewer. The event log can contain valuable information about failures of both applications and system components!

If I haven't mentioned it, read Chapter 8, "Getting Rid of the Unwanted," as well. Sometimes the unwanted is the root cause of all of our problems.

What Fails Most Often?

The things that cause serious problems with Windows XP registries and installations are:

• Removing software without using the software's "uninstall" program. If you don't use the uninstall program, entries are left in the registry that point to files that are no longer there.

• Improperly or incompletely installed software. Again, the problem is often due to insufficient disk space for the software's files, or an installation program that fails. In this case, the installation program probably updated the registry before the file copy process had completed; it then failed to undo the registry update after the file copy process failed.

• Damaged software files, caused by installing either the wrong software or wrong software version into a directory where an existing software program or version exists.

Some problems arise when software versions become mixed, or when the installation process cannot properly update one or more files.

To Repair or to Replace?

The Windows XP installation program allows you to repair a broken installation. This is nice.

This is good. This can be dangerous, too.

Generally, the repair options in the Windows XP installation program simply allow you to replace the Windows system files with fresh copies from the distribution media. These system files are the same files installed at the original installation. Now how can that be bad? Well, if you have installed a service pack, such as Service Pack 4, you may find that when you refresh the Windows installation, part of your service pack goes away. However, some things, like registry entries, won't go anywhere. This can result in some rather strange problems, to say the least. Sometimes it becomes a catch-22 situation. A service pack is installed, so you can't refresh the Windows installation; you can't remove the service pack (most service packs have an uninstall process) because the system won't run; and if you force a refresh of the system files, the system won't run to allow you to install the service pack. Oops, you're stuck, again.

Note Catch-22 is the title of a popular book by Joseph Heller. This term describes a situation in which two actions are mutually dependent and cannot be done separately. However, they can't be done at the same time, either. Like how you can't reinstall the Windows XP system files and the service pack at the same time, although to run Windows XP, you might need the service pack.

What do you do? Try refreshing the Windows XP installation using the repair options in the installation program. Immediately after that, install the same or a higher-level service pack as was installed originally on the system. That should refresh the Windows XP installation and the service pack installation. Of course, if you refresh the installation and the system won't run afterwards, you do have a problem; it may be time to reinstall Windows XP from scratch.

Note At least one supplier of Windows backup and restore software noted the following scenario

and problem: Let's say you have a system for which the system drive has totally failed. You replace the drive and install a minimum copy of Windows XP to run the restore program to recover the original disk's contents from backup. The original system included a service pack. You will probably find that you can't complete the restore. The problem is that the minimum copy of Windows XP must have the same service pack installed as the original copy of Windows XP; otherwise, you are restoring mismatched files into the system directories.

Stabilizing the System

Once a disaster has occurred, the first step is to stabilize the system. It is important that you prevent further problems or damage. After stabilizing the system, it will be much easier to fix the problem and get everything performing at its best.

Consider stabilization a systematic analysis. Start with the first step, discussed next. Can you do what this step calls for? If not, go to step 2. If so, does the system work right? If not, go back through step 1 and see if any of the hints and suggestions might apply to your system. I can't list every possible problem or fix, but I'll try to cover the most common ones here in this chapter.

When this chapter doesn't help, consider Microsoft's Internet news server at

msnews.microsoft.com. This server is accessible using one of the Microsoft news programs, such as Outlook Express or Microsoft New, or an Internet news program, such as Agent from Forte or any of the other Internet news programs available to users.

A few of the newsgroups to check on msnews.microsoft.com include (in most cases, you may substitute windowsnt, or win2000 for windowsxp to access newsgroups pertaining to those operating system versions):

Note Things change. The above list of newsgroups was current when this chapter was written, but most likely Microsoft has since added new newsgroups to their site! Best bet: get to the site and review all the newsgroups; then subscribe to those that are relevant to your problem!

Posting a query in one of these newsgroups will certainly create some response. Whether the respondents are able to assist you is something that you won't know until you try. I've posted a number of questions over the years; I've gotten help about half the time, and usually when I did not receive a useful reply, I did get the feeling that people on the newsgroup had at least tried to assist with a solution.

Warning Be careful not to lose your Last Known Good configuration. When Windows XP boots successfully, it overwrites the Last Known Good configuration with the current configuration. This could cause great gnashing of teeth later on. Try very hard to back up the registry and the operating system if possible (discussed next).