Dell Inspiron 5558

To disable in device Manager: Right click windows icon, device manager, expand Mice And Other Pointed Devices, right click touchpad driver, and then disable it, see image below:

You can disable touchpad from Mobility Center or in device Manager. To disable in Mobility Center: At the left bottom of taskbar, right click windows icon, and then Mobility Center.

I also suggest you look for a turn off switch in Mouse & Touchpad settings. Please type Mouse & Touchpad settings onto [Cortana] search box, hopefully you'll see one.

I don't see it on neither places. I don't even have mobility center!

I use Windows 10, if that will help, x64 bit system!

And I would like to add as extra, that I don't see that device on my Device Manager...

However the touchpad is working as it should!

Windows: How to disable touchpad while typing

https://youtu.be/kfDF4Zv5Wiw

I do have such place on my settings, however, I don't see settings for my touchpad!

If you still isn't able to disable touchpad then I suggest installing a free software - Touch Freeze. It turn off touchpad when you start typing, and then restarts it when you stop. Please click on link below.

http://touchfreeze.net/ 

It doesn't work either...

It appears that you can't disable the (Microsoft) touchpad however, you can post same question on the Microsoft Community forum.

answers.microsoft.com/.../