Ghost clicks on spin 5 sp513 at startup

Einsti

Hi, 
I am facing with a really inconvenient problem. Usually at starting up my computer, I am experiencing phantom touches on the screen, so I cannot log in to Windows 10. This stops after 2-5 minutes, but I cannot start working until. 
Working as a salesman it is really embarrassing in front of my clients not being able to open files etc.

I most often experience this when the charger is not plugged in. 

Once I managed to solve this issue when my computer was 2-3 months old, but Win updated itself since, and I cannot find the right way again.  
I browsed through several sites (even here...), but found nothing useful. 
Disabling touchscreen is not a solution, as I bought this kind of laptop for a reason. 

Anyone out there knows the solution, please help me!

Thanks a lot in advance!

Zsolt 

JackE

Open Control Panel. Search 'button'. Click 'change what the power buttons do' in the left panel. Click 'change settings that currently aren't available'. Scroll down and uncheck the box for fast startup to disable fast boot. Then uninstall, don't just disable, any non-Microsoft antivirus like Norton, AVG, Avast, McAfee, MalwareBytes etc. Then shut down Windows. Turn the machine back on again. Jack E/NJ