To create a bootable CD you need a bootable drive which can be used as model for the bootable CD. Generally there are three kinds of bootable CDs:
1. Floppy emulation: To create the bootable CD you need a bootable floppy disk as model. Such a CD, behaves after booting just as if a floppy disk would have been inserted into the floppy drive. This also true for the drive letter which is of course 'A'. The floppy disk drive (normally 'A') may then be accessed through the drive letter 'B'. The amount of the boot data is of course limited by the maximum capacity of the floppy disk (for example 1.44 MB).
2. Hard disk emulation: The model for such a CD is a bootable hard disk drive. The bootable CD behaves as if it were drive 'C' after booting. Your old drive 'C' may be accessed through the drive letter 'D', drive 'E' becomes 'F' and so on. Because a CD can only store up to 640MB the size of your model drive must not exceed 640MB. For example, if you have a 2GB hard disk with a single partition, then it's impossible to use this drive as model for a bootable CD. All you can do in such a case is to change the size of your hard disk partition. Normally, all data is lost if the partition sizes is changed using FDISK. But there are several tools available on the market which allow partitioning changes without losing data.
3. No emulation: This feature is designed only for professionals, who want to create their own hard disk and CD-ROM drivers. This method for example is used for Windows NT 4.0 Server CD.
The model for creating a bootable CD may be either a logical drive (all those drives which may be accessed through a drive letter; for example 'C') or an image
file of a drive. Such image files contain all sectors of a drive stored in a file. Such files may for example be created using 'Norton Disk Editor' or 'WinImage'.
A very sad limitation of bootable CDs is the fact that currently no high level operating system like Windows 95/98 or NT may be booted from a read only device. This limitation exists because all these operating systems try to write on the boot device during the boot process. Of course it's just impossible to write to a CD-ROM drive. The resulting write error is fatal and causes the boot process to be aborted. Bootable CDs exist for other platforms like MacOS or Unix for several years and are used with great success.
So in the end good old DOS is currently the only operating system that may be booted from a CD. Of course, you can create a Windows 95/98 boot CD and interrupt the boot process by pressing F8 at the right time. Booting only DOS again should work perfectly.
Bootable CDs may be created only under Windows 95/98or NT.
1. First step is to create a new bootable ISO compilation. This can be done by clicking the menu command „File" -> „New...".
2. On the left side of the dialog please choose the icon „CD-ROM (Boot)".
3. At this point you can see the property page „Boot". The upper part of this page is used to select the kind of model you have as input for the bootable CD. You can choose whether you want to use a logical drive or an image file as model for your bootable CD.
Note: If the desired input device does not appear in the list of possible model drives then the reason is probably the size limitation for bootable CDs. The logical drive's size may not exceed the capacity of a CD; that means 640MB.
Note: Please consider that you need to have administrator rights to be able to create bootable CDs using Windows NT 4.0. This behaviour is by Microsoft's operating system design and was chosen to prevent hackers from accessing other user's (possibly secret) files. But to create bootable CDs all sectors of a logical drive must be accessible. And the only user who's got the permission to read all sectors using Windows NT is the supervisor.
4. The lower part of the boot property page contains detailed settings for bootable CDs. These settings normally are dimmed indicating that Nero will check and set all the expert options automatically for you. If you choose to use an image file as model for the creation of a bootable CD, then Nero can't automatically choose those settings for you. In this case, or if you choose to define these settings manually, you can do so. Of course you're responsible for the resulting CD. If the settings are incorrect you will get an incorrect bootable CD...
5. You can now click on New. The ISO compilation window opens.
6. If the File Browser has not yet been opened, you can do that now by entering the VIEW>New File Browser command or by clicking on the File Browser icon.
7. Click on the desired data files in the File Browser with the mouse and then drag them into the compilation window.
Note: you can burn a bootable CD without data on it. In that case, you don't have to compile files.
8. Now open the Write CD dialog. The easiest way to do this is to click on the Write CD icon in the toolbar. You will then go to the Write CD dialog box, which will undoubtedly look familiar to you:
9. It is the same box which you saw for the creation of a new compilation, only now the Burn property sheet is shown on the top.
You will see several boxes, of which some have already been selected. All of the preferences may now be examined and changed if necessary.
10. Confirm by clicking on Write.