The new version 14.04 LTS 'Trusty Tahr', needs no fake-PAE. Use forcepae in the standard installers

The new version 14.04 LTS 'Trusty Tahr', needs no fake-PAE to work with Pentium M and Celeron M CPUs. Instead you use the boot option forcepae and boot from the standard desktop installer and alternate installer for 32-bit systems. I think Lubuntu and Xubuntu will work well in laptops with these CPUs. Xubuntu has a medium light desktop environment and Lubuntu has an ultra light desktop environment. Try both to find what is best for you.

This is a detailed description how to use forcepae.