Q My question is simply this: How do I create a bootable CD-ROM? I believe it isn't quite as simple as making a bootable floppy disk.

A Creating a bootable CD used to be a tedious and time consuming process, requiring intricate knowledge of DOS, hexadecimal, boot sectors, disk editing programs and large amounts of patience.

Fortunately, the whole process has recently become much easier due to the implementation of the El Torito standard, which specifies how and where files should be arranged on a CD to make it bootable. For example, according to the El Torito specifications, the first 15KB on a CD must contain a boot record which indicates if the CD is bootable.

However, despite the new standards and the wide availability of easy-to-use CD mastering software, making a bootable CD is still more complicated than making a bootable floppy disk.

To make a bootable CD you will need: one blank CD-R disk; a CD recorder; CD-R burning software such as Adaptec's Easy CD Creator; and one blank high density floppy disk. Then follow these steps to create a bootable CD.

1. Make a bootable floppy disk for your system. A bootable CD requires an image file that is an exact copy of a bootable disk, so this disk will be the foundation of your CD. In Windows 95, select Start-Settings-Control Panel, and then Add/Remove Programs, click the Startup Disk tab, insert a blank floppy disk and click the Create Disk button. Next, copy the files autoexec.bat, config.sys, mscdex.exe, sys.com and xcopy.exe from your hard drive to the floppy. To be able to access any other files you place on the boot CD, you will also need to copy the real-mode CD-ROM drivers for your system to the floppy, and edit the autoexec.bat and config.sys files to load the drivers from it.

Test the bootable floppy disk. Boot your PC from the floppy and check that you can access the CD-ROM drive, then write-protect the disk.

2. Burn the CD. Fire up your CD burning software. To record the CD in Adaptec Easy CD Creator, select File-CD Layout Properties, click on the General tab and type a name for your CD in the Volume Label box. Select the Data Settings tab, choose ISO9660 from the File System box, and check the Bootable box. Click on the Properties button and select the Any MS-DOS 8.3 character file names option, then click the OK button. When prompted, insert the bootable floppy disk and click OK. After Easy CD Creator has read the boot information from the floppy disk, it will add two files, Bootcat.bin and Bootimg.bin, to the CD Layout window. Add any other files you require on the CD and click the Record button on the toolbar.

A bootable CD will only boot PCs that support the El Torito standard and allow the BIOS to control the CD-ROM drive. Most modern hardware complies with the El Torito specifications, but pre-1996 hardware probably won't. To check if your PC can boot from a CD, open up the BIOS setup program and head to the section called Boot Options or Boot Sequence. If your PC can boot from a CD, CD-ROM will be listed as one of the Boot Options, and you should select it to be able to use a bootable CD in your PC.

For more information about creating bootable CDs and using them to backup your system, it's worth checking out the Australian Bootable CD FAQ, which is available at www.ozemail.com/~rossstew/drs/bootcd.html.

Caption: Applications such as Adaptec's Easy CD Creator make it easy to create bootable CD-ROMs