At a certain point during the installation of FreeDOS, one has to choose which optional packages to install. The packages selected by default are marked with Xs in their repective boxes. One then has to place Xs in the boxes of the unselected packages.
I do not know how to make the Xs in the boxes. I can move between boxes with the arrow keys, but cannot find any way to make an X. I have tried to type the X. I also tried SHIFT + X, to no avail.