windows 10 – Laptop’s inbuilt keyboard is not getting disabled

One of my laptop’s keys (/) was continuously getting pressed on its own. Maybe it was stuck or it was dirt, I don’t know, so to fix it I disabled my laptop’s inbuilt keyboard by following this procedure:

Device Manager -> Keyboards -> Keyboard with PS2 written (it was the inbuilt keyboard) -> Right click -> Uninstall device.

Now it worked perfectly (i.e. laptop’s keyboard stopped working) and I began using an external keyboard which was all fine until today when Windows 10 got an update of about 409MB, keyboard enabled itself (I don’t know how). And when I try to disable it, it isn’t getting disabled.

I tried the same procedure and it says to restart but the keyboard is working on restart too.

How can I completely disable my keyboard ?