I'm having problems to update my itunes...it keeps asking for the admin password. I don't have that password. I'm trying the installation CD but it is not working!!! Help!!!

Boot from your Mac OS X installation disc, either the retail copy you bought or the one which came with your Mac when you bought it. Insert it into the computer and then double click on the Install Mac OS X icon and you'll get a window with a big graphic and a restart button. Click on it, and your Mac will restart and go straight to the install process. Click through the steps of Installation far enough until you get the regular set of choices on the menu bar. Click on the Utilities menu and choose Reset Password. Using this tool, you'll be able to change your password to something you know. Then choose Quit from the Installer menu and when your computer restarts, you'll now know the password.

Thank you very much for your reply! I did all that but I have a doubt...I have two accounts available to reset the password. One is my user - that does not have administrator rights, and the other is the system administrator (root). Should I change this one?! And which is the user for this account?! Thank you!!!!! Manuela.