IBM B50 - Manual (Page 59)

The following describes the choices available on this screen.
Select Software: This option, if supported by the operating
system, allows you to choose which operating system to use.
This option is supported by AIX. However, not all operating
systems support this option.
If you receive an informational message saying that no
operating system is installed, then the system information in
nonvolatile storage may have been lost. This can happen if the
battery has been removed. To correct this situation, refer to
the bootlist reference in your AIX operating system
documentation.
Software Default: This option, if supported by the operating
system, enables you to select a default operating system for
your server.
Install From: Enables you to select a media drive from which
to install an operating system.
Chapter 3. Using System Management Services 3-7