Would appreciate some computer help

[drfred]

One of my crack staff used my computer one evening and left it so that when I pull up internet explorer or a spreadsheet, it obliterates the bottom
toolbar. I have to minimize my spreadsheet to bring up another open spreadsheet. What I have facing me is the Explorer icon in the left hand corner, next to that "done" and on the far right is "a globe" next to "Internet".
I have been playing with toolbars, etc. up top and can't bring the lower toolbar back when any program is running.
Thanks,
Fred