in my acer after installing windows 10 my touchpad is not working?

If you tried updating the drivers manually using Device Manager, try letting Windows find some drivers for you. In the Settings app, go to Update & Security > View optional updates. Then, expand the list of optional drivers that Windows has chosen, and try installing them.

If it’s anything like my E6440 when I did a clean install of 10 (already had a digital entitlement, so I just had to pick the correct version) there may be a newer version of the touchpad driver from Microsoft and a version from the manufacturer of the PC. The only difference I can find is a Cortana multi-touch command I disabled as I don’t like to use it beyond local search of the PC, and a newer version. It’s worked fine so far.

Normally I install the reference version from the downloads page and overwrite what comes in automatically, but the Intel HD 4600 driver is newer, along with the Intel 6235 driver being newer and without the need for a separate BT driver now. The same usually goes for the trackpad in cases where there’s a driver from Microsoft.