I am new linux user especially on Ubuntu. I've installed Ubuntu Lucid Lynx using in Windows XP using Wubi. When I'm trying install java, it require su command, the instruction on java said I have to put my administrator password on it. Everytime I tried my password, it wont work. Then I realized my account is not an administrator, so I change it to Administrator, but still doesnt work. Any help?
do you mean su comand, or sudo command ? - the sudo command needs the password of the normal user, and su needs the root password. By default in ubuntu the root account has no password and you get to it by "becoming root" via sudo.
normal user ->
sudo has configuration to say who can run which commands as root, but by default the user you created at install can do what you need.
does that help / make sense ?
In the long run though, in this particular instance you'd be better off doing
On Ubuntu, you are "supposed" not to need to use the "su" command. Rather than use "su" to get root priviledges until you use the "exit" command, you are supposed to preceed each command with the "sudo" command.
(Note that the prompt changes from "$" to "#" to show that you are root.)
As an alternative, you can use the command "sudo su -" rather than "su" to become root in Ubuntu.