how to erase the definitly the name of an account

[taht]

sorry for my poor english skill,
but as a new user (under fedora 6 and gnome) I try to create an account
with gnucash for my personal need and now I decide to delete it .
I want to start again gnucash 'since the beginning', and to thus erase
completely the account created, I had the choice on the menu to erase
this account and the operations and it was ok, but then by starting
gnucash again, it always displays the name of the old account under file
in the menu. So my question is this one : in which file can hide the
name of this old account previously created and how to delete it
definitively?
thanks