The Toolbar thing that runs across the bottom of my screen, with the start button etc on, has grown to about 4cm deep. It used to be just over a cm deep, but I havent done anything that Im aware of. What might |I have inadvertently done, and how to I get back to normal please. Thanks.

hover your mouse over top of task bar until the arrow turns into a double ended arrow, left click and drag back down, and then right click on task bar and left click on lock task bar.

http://windows.microsoft.com/en-gb/windows7/resize-the-taskbar

The top edge of the tool bar is moveable. Point your cursor to the top edge, it should change to a double-headed arrow, hold down the left mouse button and drag it back down to the bottom of the screen (hope that makes sense!)

(eta - oops...cross-posted Willo!)

After that right click lock toolbar.

I did mean to say right click, for some stupid reason I said left. doh

Thanks everyone, thats got me back to normal. Great.