You may need to try an external keyboard to get into the laptop. Turn it off and then connect the external keyboard. Then once in Windows, try the following to see if you can fix it.

1. Uninstall the keyboard driver.
2. Reboot the computer (without reinstalling the driver). 
3. When it restarts, it should reinstall the driver on its own.

Once back in, with the external keyboard still attached, shut down the computer again, detach the external keyboard and try starting it up without it.

If this doesn't work, then it could be the keys themselves that are the issue.

You may also want to try updating the Synaptics Driver if the above doesn't help.

EXACTLY this happened to me, for the third time actually, I have an Acer Aspire E 15 (e5-575g), I was googling as usual, and suddenly the keyboard died, without any crash-report, which is found on the keyboard device property.

I tried EvErYtHiNg, uninstalling the keyboard drivers (with direct restarting after uninstalling and without restarting directly after but doing it manually).

I tried updating the drivers in 2 different ways, from online search and from searching on device.

I toggled the "filter keys" option and restarted the laptop after every change, but nothing changed.

I tried updating Windows 10.

I called ACER support, no solution from the team.

So I turned off the computer and left it for an hour.
And when I turned it back on everything worked. All keyboard were back on.

The interesting thing is that None of the above tries ever resolved this issue, so I can only assume this is a hardware problem and if anyone who reads this facing the same issues, my recommendation is, send it to service! Because things like this will happen again.

On Acer Aspire E 15 (E5-576-76J8)

• My whole keyboard stopped working from a day to the next. It's not a software problem, also in BIOS I can't use the keyboard.
• I know it to be hardware-related, as very rarely, after minutes of randomly tipping on it, it will take an input.

My guess is that the issue is with the ribbon cable for the keyboard that other users have talked about. However, this seems like a rather unsafe part to manipulate (and as some of you might know, it's a pain to open that acer laptop, as one really needs to remove all roughly 10+5 screws on the back).

Does anyone else have feedback before trying this seemingly error-prone DIY repair? Also, Acer, really disappointed. I haven't used the laptop much, it never fell down, I don't live in an environment with moist air...

Thanks,

Lionel