On IML systems, if a power-on password is set, the system always  attempts to load the IML image (POST and BIOS code) from the System Partition. The only way to load IML from the Reference Diskette is to first erase the power-on password. For example, if the hard disk is dead, and a power-on password set, and then you boot the Reference Diskette, you will get an error. The system is trying to load IML from an inoperable hard disk. To avoid this, you must first erase the power-on password first. (If there is a privileged-access password set, you do not need to erase it, but  you will be prompted to enter it.) 
    On FLASH systems, POST and BIOS code is contained in the FLASH EEPROMS. Regardless of the condition of the default hard disk, you will always be able to load diagnostics from the Reference Diskette. 
    On Model 90 and Model 95, be sure you have the correct type of Reference Diskette (there is more than one type). 

(For  FLASH and IML systems, see "PS/2 System Specifications" ) 

After you replace the default hard disk drive, that is, the drive with the System Partition, you must recopy all of the system programs onto the replacement hard disk. To recopy the programs: 

  1.Start the system using the backup copy of the current System Partition. 
  2.Select Backup/Restore system programs from the Main Menu. 
  3.Run the Restore the System Partition option to load the IML image (if it is an IML system), the system programs, and any user and advanced diagnostic programs onto the default hard disk drive. 

Notes: 
    1. If the user's backup copy of the System Partition is incomplete, you will not restore the entire System Partition. If this
occurs, after you have recopied the IML image, get the option diskettes and use Copy an option to recopy the option files
onto the System Partition. 
    2. If the IML image is loaded onto the hard disk, but the operating system is not loaded, either the Insert-Diskette icon,
an I9990305, or a text message appears on the screen.