Reset the Active Partition via FDISK.
Power on the computer.
The a:\ prompt appears.
The error No SCSI BIOS Installed usually means that either no bootable device is attached to the SCSI controller or no bootable media has been installed in the respective SCSI device.
A server that previously booted successfully into the operating system (OS) will no longer boot and hangs on the message No SCSI BIOS Installed.
This problem generally arises during configuration of the server or after new disk space has been added. In order for the system to boot into the OS successfully, the partition that contains the system files must be marked as active. If it is not, the system will behave as if there is no OS installed. The error No SCSI BIOS Installed usually means that either no bootable device is attached to the SCSI controller or no bootable media has been installed in the respective SCSI device, or both.