After I installed a Creative Labs' Creative GeForce2 MX PCI card into my system, I had what I assumed was an intermittent PCI bus bug for about a year. Then, a serious problem occurred. Apparently, this PCI card sometimes breaks the PCI bus protocol rules when running heavy-hitter OpenGL applications, causing the machine to halt. I emailed technical support for SuperMicro (the manufacturer of my Intel 810-based motherboard), but I couldn't get a straight answer to explain the cause of the system halt. I figured that the BIOS must enter a system halt routine to prevent further data corruption.
On one occasion, my computer crashed three times in less than 15 minutes. I received the error message HARDWARE MALFUNCTION, the system has halted—Contact your hardware vendor. Each time, I was able to hard reset the machine and boot Windows 2000. But the fourth time my computer halted, the C:\winnt\system32\config\system registry file got corrupted. I don't know why the registry was even open at the time. I couldn't boot the machine, and I received an error message saying the C:\winnt\system32\config\SYSTEMced file was corrupted. I thought the message was odd because this filename doesn't exist. I assumed that ced was junk that got appended to the error message.
I didn't want to reinstall Win2K and all my applications and recreate my Microsoft Internet Explorer (IE) Favorites. I attempted a repair installation by booting from the Win2K Professional CD-ROM. But the install routine couldn't locate a current installation of Win2K because I didn't have a current Emergency Repair Disk (ERD).
Next, I performed a parallel installation of Win2K Pro to a directory other than C:\winnt (i.e., C:\winntfix). I could finally access the NTFS 5.0 (NTFS5) boot partition and try to determine which file was corrupted and how to fix the system without fully reinstalling the OS and applications.
I discovered that along with the C:\winnt\system32\config\system file is a file called C:\winnt\system32\config\system.alt. You can use the system.alt file to recover the system hive. I renamed the system file to system.bak, and I renamed the system.alt file to system. (The Microsoft article "Using System.alt to Recover the System Hive" at http://www.support.microsoft.com/?kbid=151247 discusses this solution.) Then, I crossed my fingers, rebooted, and selected the original installation in the boot loader screen. To my amazement, the system booted just fine. I checked the system and system.alt files—both were rewritten after the successful boot.
I was lucky; my problem could have been much worse. I learned the importance of having current backups, even on a machine that's just a workstation. After I solved my problem, I made backups of the registry files to my file server. Because I don't have a tape drive, I also backed up other important items such as C:\documents and settings\sdhoeppner.
In hindsight, I could have used the Win2K Pro CD-ROM to boot the machine into the Recovery Console (RC) and renamed the files there. However, I still think that having a parallel installation is handy in case you run into a problem that isn't as easily fixed as mine was.