Although traditional floppy emergency repair disks (ERDs or boot disks) can be a lifesaver when it comes to troubleshooting an OS crash, they suffer one significant drawback. They are limited to only 1.44 MB of space—and the boot files (Io.sys, Msdos.sys, and Command.com) consume a sizable amount of this space. However, you can create a bootable CD from a floppy disk that functions very similarly to a boot floppy, with greatly expanded space available for drivers, utilities, and anything else you might need.
The advantages of CD over floppy
There are three advantages that a bootable CD has over a bootable floppy. First, a CD can hold a lot more data, so you can include repair utilities that just won’t fit on a floppy. Second, CDs tend to be more durable than floppies. You don’t have to worry about a CD accidentally getting erased or mangled by a hungry drive head. Finally, CDs are virtually virus proof; assuming that you create the CD on CD-R media and the system that you use to create the CD is clean. And there’s no danger of accidentally infecting the CD with a virus from the PC that you’re trying to fix.
Start with a floppy
For the process I describe in this article, you'll need a floppy boot disk. Although you can create an emergency repair CD without first using a floppy, the process is much more difficult. And if you create a floppy first, you can test that disk to make sure it works and meets your needs before investing the time to burn a CD. Before you begin creating your bootable CD, I highly recommend you read my previous article on creating the perfect floppy emergency repair boot disk.
Creating the boot CD
For the bootable CD creation techniques outlined in this article, I’ll be using Easy CD Creator 5.0 Platinum from Roxio, which comes bundled with many CD-R/RW drives (Figure A). You can apply the general principal of these specific techniques to any CD-burning utility that allows you to create a bootable CD, such as Ahead Software's Nero Burning ROM.
Begin by launching Easy CD Creator and selecting the Make A Data CD option followed by the Data CD Project option. You’ll then see the main Easy CD Creator screen. Select New | Bootable CD from the File menu. Next, you’ll see a dialog box asking you for information about your bootable CD, including its type. The type options are Floppy Disk Emulation (1.44 MB), Floppy Disk Emulation (2.88 MB), and Hard Disk Emulation. For this particular project, select Floppy Disk Emulation; otherwise, Roxio will copy the boot files from your hard disk. I also recommend using Roxio's default settings for the Load Segment and Sector Count options.
The bottom section of the dialog box asks if you want to generate an image from a floppy disk or if you’d rather use an existing image file. At this point, insert your boot disk into the computer's floppy drive and click OK. Easy CD Creator will read the floppy's contents and display them in the project workspace. Regardless of how many files are on your boot disk, you’ll only see two files appear in the workspace, Bootcat.bin and Bootimg.bin, because these files represent an image file rather than the individual files contained within the image.
You can now drag-and-drop any files or folders that you want from the hard disk to the CD project workspace. This is when you'll want to select the utilities to place on your bootable CD. I suggest including some data recovery utilities, disk editors, and antivirus programs. Just remember that you can include any utility you want, but you’ll only be able to run those utilities that you can operate from a command line.
Now you're ready to create your CD. Make sure a blank CD is in the drive and then click the Record button. Finally, verify the recording speed and the drive letter and click the Start Recording button.
Using the CD
The procedure for using the CD will differ from computer to computer. On some systems, you’ll have to modify the CMOS before the system configuration before the system will boot from CD. On other systems, simply place the bootable CD into the drive and power up the system. Still other systems will detect a bootable CD in the drive but will require you to press a key to boot from the CD rather than from the hard disk.
If you’ve created the boot CD using the image from the bootable floppy disk that I described in my previous article, you first should see the boot menu asking you to select a CD-ROM drive type. At first, this might sound really strange. After all, why tell the system what type of drive is in use when the system apparently already knows? Remember that just because the system booted from CD doesn’t mean the operating system knows what type of CD-ROM drive is in use. It only means that the system’s BIOS knows about the drive. If you want the CD-ROM drive to be accessible through the command prompt, you must still load the necessary drivers.
After selecting the CD-ROM drive from the list, the boot disk will load the drivers and detect the drive. You will then be taken to a command line. All CD-ROM drives will be accessible by drive letter, as will any FAT16 or FAT32 partitions.