Aspire E 15 Problem with Elan touchpad

Mercurial laptop this one. I am currently experiencing lag/judder and beeping when I move my cursor. Started recently. It feels as though it's to do with the laptop just not keeping up with the intended movement, somehow. The system sounds are off. The beep is not a hardware code beep.

I have Win10 and Office 365.

I have been experiencing problem whereby the screen brightness settings reverse every time the laptop sleeps - so pressing the up button results in a darker screen and the down button results in a lighter one. When I next open the lid, up is light and down is dark.

On advice, I have installed older (8.1) graphics drivers to solve the problem (which it hasn't). I have no idea if this could be relevant.

I then downloaded a free app to search for and install all the up to date drivers for everything instead. This hasn't helped either.

I am also (coincidentally or not) having problems with excel - all the data appears to vanish (it's still there, but not visible on the screen) ...and then comes back in chunks. If I close the file and open it, it's fine again. Again, it feels as though the system just can't keep up - admittedly there are lots of formulae but there are only 100 or so records and maybe 30 columns, not exactly using the whole range of possibilities.

I am intermittently receiving a message EAccess Violation Something about ASHelper.exe 00005736 and a code 00405736 and read of 00000004.

Hope someone can help!

Many thanks.