Unable to login to console Solaris 10 SunFire V240 server

Please somebody help me I've tried rebooting from CDROM and everthing else imagineable. Always end up back at console login prompt, yet OS(Solaris 10) cannot find credentials even for root. This is where I hit a dead-end.I need to somehow get to the Solaris SU prompt<#> , so that I can continue on . How can I get around the console login requirement and how do I re-create the root user with all the necessary credentials originally shipped with the server?

Do I need to completely re-install the OS from CDROM ? The system was shipped with two OS DVD's:

1/06 Solaris 10 OS for x64/x86 DVD and

1/06 Solaris 10 OS for Sparc DVD.

[664 byte] By [mayewil] at [2007-11-26 11:18:32]