Imagine this: You hit the power switch on your Windows or Linux PC, and the system starts to boot, but stalls. The power's on, the hard drive is spinning, but nothing's happening. You restart the PC, but the same thing occurs--what next? You might try booting from your original operating system setup CD. If the CD drive is operating properly, and if you know what you're doing, you might be able to boot to a non-graphical command-line or "Recovery Console" version of your operating system. But at best, this won't be a simple thing, and won't automatically provide you with the tools you need to diagnose or repair whatever went wrong with your system. At worst, you won't be able to do much of anything useful at all. What's more, for most normal users, inserting the setup CD will only bring up the original installation routine, which offers to completely reinstall your operating system. Not only will this overwrite your existing setup (including your preferences), it may do nothing at all to correct whatever was preventing your system from booting in the first place.

What about the "recovery CD" that some system vendors provide? While some of these CDs do have basic diagnostic routines and repair tools, most are extremely generic and are geared primarily to reformatting your hard drive and restoring the original factory setup of the operating system, wiping out all your data files and customizations. And even then, you have no guarantee that the original problem will be solved.

You could try a generic, preconfigured bootable CD: For example, there's the "Ultimate Boot CD" but it contains just five DOS-based diagnostic tools. Or there's the more complete "911 Rescue CD" or the similar "SuperRescue" CD for Linux. The tools on both CDs are good, but still are limited and are based on a generic, lowest-common-denominator approach to system recovery and repair.

A last option, if you're from an older school, might be to try a "boot floppy;" a floppy disk that contains just the essential files for a bare-bones restart of your PC. This approach is conceptually sound--in a way, you can think of a boot floppy as a kind of skeleton key that allows you to "open up" your PC for low-level diagnostics or repair. But floppies hold only 1.44 Mbytes of files. That's simply not enough room to hold a full array of fix-it tools. Unless you've already collected a complete library of floppy-based low-level repair tools, having just a boot floppy alone won't get you very far. And even if you happen to have a drawer or carry-caddy full of floppy-based tools, it still won't be fast, easy, or pleasant to rummage through them, trying to find what you need.

A Better Way
Now imagine the same initial scenario, but with a different outcome: You hit the power switch on your Windows or Linux PC, and the system starts to boot, but stalls. The power's on, the hard drive is spinning, but nothing's happening. You restart the PC, but it just won't boot normally. So, you insert a single custom CD--one you made yourself--into your drive and boot from that. That one CD contains not only the necessary files to get your PC started, but also contains everything you need to diagnose and repair almost any kind of system trouble. In fact, it's packed with an entire software toolkit--potentially as much as about 500 floppies' worth of software--all in one place, right at your fingertips. What's more, the CD isn't some kind of cookie-cutter, lowest-common-denominator tool, but one that suits your specific preferences and needs; one that's customized for your unique combination of hardware, software, and skill level.

Having a custom-boot CD like that can be incredibly useful whether you're supporting an office full of PCs or just one. At one end of the spectrum, it means that support staffs or IT techs can carry, on one slender CD, most or all of the software tools they need to service or set up multiple brands, types, or generations of PCs in an enterprise.

At the other end of the spectrum, it means that a single end user can have everything--even perfect disk images or backups of their system--on a single CD, allowing any level of software repair. In my own case, supporting about a dozen mixed Windows and Linux PCs, I've built customized DOS boot CDs that contain not only a full range of diagnostic/repair/setup tools, but also hold copies of all the drivers used by all the machines; plus copies of all my environment-specific configuration files and data.

Here's a small example of how this can help: I have nine different brands of network cards in use on my office systems. My boot CD toolkit has a folder called NICs that contains nine subfolders, each holding all the driver files for one of the network-card types. No matter what PC I'm working on, and no matter what operating system is on any given machine, or what operating system I may switch to, I have the correct network drivers instantly at hand.

Same for audio, video, motherboard chipset, and other drivers; BIOS flash updates; and more. Everything--and I mean everything--is there on one CD. What a time saver!