What lead you to believe it is updating the firmware?
In detail, what happens when you power on the machine? take &post picture here if you can. click on camera icon in this posting software.
Try a safe boot.
This site provides more information. Best for older machines. Note, serial number is sent in the clear.
"A serial number is a unique, identifying number or group of numbers and letters assigned to an individual piece of hardware or software. It's used for various things depending on the product / brand but what is your Mac's serial number for and more importantly... what is it hiding and what can it do for you ?"
http://www.appleserialnumberinfo.com/Desktop/index.php
or
This site provides more information, but lacks security too.
"A serial number is a unique, identifying number or group of numbers and letters assigned to an individual piece of hardware or software. It's used for various things depending on the product / brand but what is your Mac's serial number for and more importantly... what is it hiding and what can it do for you ?"
http://www.appleserialnumberinfo.com/Desktop/index.php
http://www.chipmunk.nl/klantenservice/applemodel.html
( hint by K Shaffer )
You may want to run these "standard" fixes if the problem persists.
1) Check the amount of free space on your harddrive. You should have a several gigs free.
2) You should run disk utility
from you startup dvd
a) verify the disk
b) update your permissions.
3) Try a safe boot.
Shutdown your machine. Hold down the shift key. Poweron. Wait awhile Wait awhile while you harddrive
is being checked.
http://support.apple.com/kb/ht1455