lubuntu 12.10 [64 bit]

Lubuntu (pronounced /luːˈbuːntuː/ "loo-BOON-too") is a lightweight Linux operating system based on Ubuntu but using the LXDE desktop environment in place of Ubuntu's Unity shell and GNOME desktop. LXDE is touted as being "lighter, less resource hungry and more energy-efficient".[3][4][5][6][7]
Lubuntu received official recognition as a formal member of the Ubuntu family on 11 May 2011, commencing with Lubuntu 11.10, which was released on 13 October 2011.[8][9][10]
Like Xubuntu, Lubuntu is intended to be a low-system-requirement, low-RAM environment for netbooks, mobile devices and older PCs. Tests show it can use half as much RAM as Xubuntu, making it an attractive choice for installing on older hardware being refurbished for charitable distribution.[3][11][12]