DOCUMENT ID: 1509-02 SYNOPSIS: Restoring the multi-boot menu OS RELEASE: Any OS PRODUCT: Multi-Boot menus KEYWORDS: boot menu solaris interactive msdos multi SYMPTOMS: The multi-boot menu for an x86 system is lost, usually after installing a new version of MS-DOS. DESCRIPTION: After upgrading MS-DOS, or some other OS on your PC, the multi-OS boot menu has disappeared and only that OS boots. SOLUTION: Using MS-DOS to Restore The Boot Menu If you are using MS-DOS version 6.x, the version of FDISK that ships with that system can set non-DOS partitions to be bootable by making them the "active" partition. If you are using MS-DOS 5.0 or less, the FDISK for those systems can only make the DOS partition active. As soon as you make the partition with the multi-boot control the active partition, you will see the multi-boot menu again. Using Solaris to Restore The Boot Menu With Solaris you can use the installation floppy to boot under the Unix system. With Solaris you will be offered the chance to boot from the CD, network, or hard drive; depending on which boot disk you use. Do not select the hard drive, because it still does not have a boot menu enabled. Select either your CD or network boot device, whichever is appropriate. Stop the installation as soon as possible and return to a shell prompt. Once you have returned to a prompt, run the fdisk program for Solaris using the -I prompt to go into interactive mode. From there it is a simple matter to make the Solaris partition the active one. This will enable the Solaris multi-boot menu again. Using Interactive to Restore The Boot Menu You can use the installation boot floppy and stop the installation as soon the system is up. You can now use the fdisk program that comes with Interactive to enable the Interactive partition. This will enable the Interactive multi-boot menu. Using System Commander This is a program created by V Communications that can allow for the booting of MS-DOS, Windows '95, Windows NT, OS/2, Solaris, Interactive Unix, SCO Unix, Linux, Free BSD, and probably some other OSes as well. One advantage of this method is that no single OS is in control of the booting process. You do need a minimum MS-DOS FAT partition to hold System Commander, but you do not have to have MS-DOS itself. A second advantage for programmers is that you can have multiple versions of MS-DOS installed. By placing each version into its own directory, including the CONFIG.SYS and AUTOEXEC.BAT for that version of DOS, you can select the version you need at a particular time. This is also useful for some games that require an older version of DOS for some reason, or maybe the Japanese version of DOS versus the English version, etc. A third advantage is that System Commander will "hide" partitions for you when booting from a particular OS. This is needed sometimes when the partition type for one OS looks the same as that for another (Linux and Solaris are like this). By hiding the partition, you can prevent a "foreign" OS from accessing and corrupting a file system. Using Other OSes I can't give the exact procedure, but something similar may be possible for other OSes that provide a multi-boot control, like Linux, OS/2, and Windows NT to name a few. Generally, you can start the install procedure, stop it before it goes too far, and use the disk partitioning software that came with the OS that provides the multi-boot menu service. DATE APPROVED: 09/05/95