mysql > locked out of my server!

[angst]

Hello!
I just setup a new server today, and I'm already locked out of mysql ( yes i'm a n00b ).

It's Ubuntu. I installed the server this morning, came back to my office, and I can't do anything in mysql.

I login like:
mysql -u root
that gets me in.

then i run:
UPDATE mysql.user SET Password='mypass' WHERE User='root';

and get this error:
ERROR 1142 (42000): UPDATE command denied to user ''@'localhost' for table 'user'

I've tried removing the server, then reinstalling, and still have the same issue. any ideas would be a big help!


------- UPDATE--------
ok, i've just tried removing it again using:
apt-get --purge remove mysql-server-5.0

which went fine, however now I'm getting this error on reinstall:


root@harp:/home/sites/# apt-get install mysql-server
Reading package lists... Done
Building dependency tree
Reading state information... Done
mysql-server is already the newest version.
0 upgraded, 0 newly installed, 0 to remove and 31 not upgraded.
2 not fully installed or removed.
After this operation, 0B of additional disk space will be used.
Setting up mysql-server-5.0 (5.0.51a-3ubuntu5.1) ...
* Stopping MySQL database server mysqld [ OK ]
/var/lib/dpkg/info/mysql-server-5.0.postinst: line 143: /etc/mysql/conf.d/old_passwords.cnf: No such file or directory
dpkg: error processing mysql-server-5.0 (--configure):
subprocess post-installation script returned error exit status 1
dpkg: dependency problems prevent configuration of mysql-server:
mysql-server depends on mysql-server-5.0; however:
Package mysql-server-5.0 is not configured yet.
dpkg: error processing mysql-server (--configure):
dependency problems - leaving unconfigured
Errors were encountered while processing:
mysql-server-5.0
mysql-server
E: Sub-process /usr/bin/dpkg returned an error code (1)
root@harp:/home/sites/#

any ideas?




thanks in advance for your time!
-Ken