Archlinux has least memory usage compared to Debian and Ubuntu.

I install any Linux distribution after copying the contents of ISO to a spare partition on the hard disc. For Archlinux I found this page. As suggested I downloaded FTP USB variant of the ISO from this page. I copied the contents of the ISO as suggested using dd command. The document suggest to chain load the installation boot menu. It did not work for me, therefore, I made following entries in /boot/grub/menu.lst to boot the installer.

title ArchLinux Installation System
root (hd0,1)
kernel /boot/vmlinuz26 lang=en locale=en_US.UTF-8 ramdisk_size=75%
initrd /boot/archlive.img

I use the USB port of my router but the installer, although, detecting it as eth1 did not work, therefore, I connected it through NIC. The installer downloaded and installed the base system. The Grub of Archlinux does not detect other operating systems on the hard disc, therefore, I did not install it to MBR.

After rebooting I made necessary entry for new Archlinux installation in existing Grub

title Arch Linux
root (hd0,0)
kernel /boot/vmlinuz26 root=/dev/disk/by-uuid/72e737f9-5faf-4103-bfe2-84f9a01c4dab ro
initrd /boot/kernel26.img

and rebooted again into Archlinux base install.

On the other PC I had opened the very elborate Beginners Guide on Archwiki. I followed it step by step to install xorg and LXDE desktop environment.

The screen of my Laptop is broken and I use it as desktop through external monitor. The ati driver of Xorg 7.3 has a bug and as expected I got blank monitor on startx command.

In order to generate xorg.conf for xvesa I used the following method:

# pacman -S hwd
# hwd -u
# hwd -x

The last command generated xorg.conf files for vesa and ati driver. I copied the vesa file to /etc/X11/xorg.conf and could boot into LXDE desktop.

I find the LXDE desktop on Archlinux having less memory usage compared to Ubuntu Cli and Debian Cli.
On LXDE+LXTerminal (Debian uses 104 against 67 by Arch)

$ free -m
  Total used free shared buffer cache
Mem:  312 67 244 0 5 32
-/+buffers/cache  29 282