So you bought a used Lenovo 100e with a stupid ELAN066C touchpad. It works in Windows just fine, other than being god-awful slow. You want to put Xubunutu on it to make it workable, except the touchpad stopped working. Ugh.
My brain is smooth, so this took me like 40+ hours to solve. I'm sure you would have solved it faster, but just in case you need help here are the steps I took to get it working. For reference, my exact computer is Lenovo 100e 2nd Gen (82GJ).