How to replace an Acer 5100 touch pad?

Before replacing the touch pad, try plugging a USB mouse or keyboard into the laptop.

If this works, it may be that the keyboard and touchpad do need replacing.

But this seems unlikely since on the Acer these units have completely separate interface units on the main board.

Removing the keyboard on Acer is fairly simple with only a screwdriver.

There are two screws on the bottom of the case, sometimes marked with a keyboard icon. Remove them and the keyboard should tilt out. Be careful not to yank the brown ribbon cable.

I suspect you have either a software problem, or a partially damaged main board.

Try booting from a "live" distribution like damnsmalllinux.org on a flash drive and see if the keyboard and touch pad work.

Good luck, hope you get this fixed.