I have dual booted to lubuntu (with Windows XP) and everytime and then I'm getting asked for my password. How do I run everything as root and not ask a password again? Ideally I wanted to run nginx but it has permission denied issues:

apathetic@ubuntu:~$ service nginx start
Starting nginx: nginx: [alert] could not open error log file: open() "/var/log/nginx/error.log" failed (13: Permission denied)
2012/08/03 20:06:25 [warn] 4762#0: the "user" directive makes sense only if the master process runs with super-user privileges, ignored in /etc/nginx/nginx.conf:1
nginx: the configuration file /etc/nginx/nginx.conf syntax is ok
2012/08/03 20:06:25 [emerg] 4762#0: open() "/var/run/nginx.pid" failed (13: Permission denied)
nginx: configuration file /etc/nginx/nginx.conf test failed