external hard drive lock out


please can someone help me!
in an attempt to make my external hard drive more secure i changed the permissions on it to no access assuming that as admin i could change this setting again but i now find that the drive only shows in disk utility and i am able to mount and unmount it but it never appears anywhere else.
the drive has the firewire symbol when it is not mounted but the name greyed out and when i mount it the firewire symbol turns into an unknown (blank) file.
if there is a way to rectify this i could really do with some help.
thanks in advance.
its ok, figured it out myself had to log in as root change the permissions then log back in as myself. nice one, i am now backing everything up to dvd 'cos i dont want to panic like that again......