I'm sorry if this not allowed here.
On one computer (maybe with a newer version of Mathematica?) the autocomplete/input assistance for functions works perfectly: when I start typing one like ComplexExpand, it displays a list of functions that start with that word so I can just hit tab. Also, if I make my own functions it learns about them and will autocomplete them.
But on my other computer with Mathematica (Version 126.96.36.199), no list shows up. I've checked in Edit->Preferences->Interface, and there is nothing to turn it on -- strangely though, there is a check box that says "Match case in command completion", which suggests to me that the feature does exist in this version.
Does anyone know how I can get it to work?