just upgraded ubuntu to version 9.04 now the system ask for a password i don't remember it

Alright so here's what you do open up terminal (Application ->
Accessories -> Terminal) and then type in "who" (without the quotes)
you should get something similar to this:

vikram@ubuntu-devel:~$ who
vikram tty7 2010-01-24 14:22 (:0)
vikram pts/0 2010-01-24 14:43 (:0.0)
vikram pts/1 2010-01-24 15:37 (:0.0)

See the first part here (vikram) says my username :) that's what you
put after passwd. The password is what you use to log in into the
computer.

--
Regards,
Vikram Dhillon

~~~
There are lots of Linux users who don't care how the kernel works, but
only want to use it. That is a tribute to how good Linux is.
-- Linus Torvalds

On Sun, Jan 24, 2010 at 3:35 PM, Keith Scott
<email address hidden> wrote:
> New question #98546 on Ubuntu:
> https://answers.launchpad.net/ubuntu/+question/98546
>
> Thereis a similar previous question and solution, however I couldn't get it to work.
> The solution was to enter
> passwd yourusername
> at 'root'
> however I don't know a username as this has never been requested before??
> Is there a similar command to find the username??
> Thanks
> Keith
>
> --
> You received this question notification because you are an answer
> contact for Ubuntu.
>

Thanks leoquant, that solved my question.