A good administrator will realize the immediate value of this tool, and the extreme threat it provides were an unscrupulous user to decide they wanted to gain access, and promptly change the password. Then they will write it down somewhere and not lose it. The former admin of a site I am administering failed it big time.
You can reset the password by cracking the case and flipping a dip switch, but who wants to down a server and pull it apart for that? Not me. Here is another way to change the password from the windows based operating system installed on that hardware.
HP made a tool called the HP Lights-Out Online Configuration utility (HPONCFG for short) that will run scripts against your host's ILO system to make changes without requiring a reboot. Finding the tool on HP's website is damn near impossible, but i found it by searching for 'cp008120.exe' on google. You need to have some prereqs installed, but if the HP installation CD's were used you may already have the prereqs (and this tool) installed. You can tell by looking under Add/Remove programs for 'HP Lights-Out Online Configuration Utility' or by checking C:\Program Files\HP\hponcfg to see if that folder exists.
Next you are going to need an admin script for resetting the password. I got it from this site: http://blog.netnerds.net/2006/04/ribcl-reset-administrator-password-on-ilo/ which also details the prereqs you need in the event that the HP installer cd was not used to setup the system. Either that or you can make your own XML file by opening up a notepad and typing in
<login password="boguspassword" user_login="Administrator">
Be sure to change "newpass" to your desired password in up above next to password value... then save it as something like resetpassword.xml in the same directory as your hponcfg.exe file. Now go to a command prompt and type in:
HPONCFG.exe /f resetpassword.xml /l log.txt > output.txt
and review the output files. Should work like a charm. All credit goes to that link i posted up above for this one... just logging it with the steps i had to follow for my own sake...