Message copied from another post just bumping it as mine is the same problem
laptop is an Aspire E5-512 which came with Win 8 and was upgraded to Win 10 (current OS) and was working fine until the HDD crashed and needed replacing. No big deal. Usually. Since the replacement, the touchpad simply doesn't work. Before listing the usual, here's what I've tried:
FN + F7.
Updating the BIOS to version 1.10 with the touchpad set to basic.
Reinstalling windows with the Win 10 drivers from the support site.
Reinstalling windows with the Win 8 drivers in compatibility mode.
Replacing the touchpad and touchpad cable.
Going back to Win 8 with the drivers from the support site.
Nothing seems to does it