Questions about PostgreSQL installation

[Hussein Baghdadi]

Hi.
I have just got PostgreSQL 8.0.4
During installation, it asked me if I want to create an account called postgresql or use my current one .
What should I do in this case ?
Another thing, during -also- the installation , it asked me for the name for the server instance.
It suggests, MY_COMPUTER_NAME\postgresql
What to do in this case ?
accept it ?
(I'm installing PostgreSQL on my system -localhost- there is no network in my case, I just want to use it as my database).
Thanks.