Also, I DO NOT want to disable my trackpad completely! I just want to stop it from clicking when I tap it.

There is no Windows key on my tablet's keyboard dock, or that would have been the first place I went. I know how to do this on a regular laptop, and have done so on every single one I've owned (about 5 so far).

So, unfortunately, that doesn't help me.

With the tablet on the dock with no USB mouse yet
- Press (Windows key+x) and choose Device Manager on the list
- On Device Manager window, open mice and pointing device and right click on the item under under it and choose disable.

This should disable the dock touchpad and now you can plug in your USB mouse, if you want the touchpad back just do the same steps but "Enable" will be your option when you right click on the item under mice and pointing device. source