Showing you how you can blow away the default system settings and get Ubuntu to behave however you want, this down and dirty book will help you take total control of your Ubuntu system by optimizing its appearance, speed, usability, and security. http://www.mediafire.com/?duwbm2zzxbm
![sudo apt-get update 出错 Updating from such a repository can‘t be done securely, and is therefore[图]](data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACwAAAAAAQABAAACAkQBADs=)