It's really hard to envision what you are talking about.
Look to your right side of the taskbar, there you should see a round button
with an arrow that looks like this < Everything to the right of that is
called the notification area, when you click on that, it will show all the
programs that are configured to run at startup, etc. To the left of that is
the taskbar, which can be divided into sections. The things that I use
frequently, I drag to the left side of the taskbar, to the immediate right
of the start button. Along that taskbar are two sets of movable bars, one is
preceded by a small set of two black arrows >> If you click and hold on the
bars, which look like two rows of small dots, you can slide them all the way
to the right, or left. By clicking and holding it, then sliding it to the
left, it allows all the applications you have open to be displayed, at least
up to a numerical point. If you slide it all the way to the right, those
applications will not be visible, however, another set of arrows will be
visible, stacked, one pointing up, the other pointing down. If you click on
an arrow, either direction, up or down, it will display one application at a
time. It might be that when you were arranging things, you inadvertently
moved one of those bars all the way to the right.
