the computer will not display drop down menu / list giving me the
options of "always hide" "hide when inactive" and "always show".

full story: i open up taskbar and start menu properties. in the taskbar
tab i click on the customize button, and up comes the customize
notifications box-the various icons and their titles are listed in the
left column and their behavior (showing or hiding) in the right.

if i then click on a behavior, a menu will be displayed with a drop
down arrow / claret but will only show the current behavior-the other
two choices will not be shown

how do i correct this?