Task bar?

I think it's termed 'Task bar' it is the one that shows normally at the bottom of my screen following the start up of my computer and someone has changed it to the left side in a column style with 'START' icon at the top and others, some at top some at bottom. How do I change the task bar back to show across to bottom of the screen. Showing at the side reduces the side view of Pinnical Studio screen and others and I have to scroll it sideways to reveal whats hidden to the right of the screen.
Many thanks in anticipation of a reply.