Help me clear my forms!

After I search on Google the previous searches still remain in the google bar! This can be very embarrasing as other people use my computer and they can see what i have been searching! you know what I mean! How can I clear my forms so that each time someone uses Google on my computer they wont be able to see what I have been searching! I tried going in control panel>internet options>Content>auto complete settings> and then clicking 'clear my forms' and unchecking all the boxes above but it doesnt work. It doesnt clear all my forms! In fact my forms remain in any other search box I have used. This is really annoying me. It has only started happening recently since I started saving websites in 'My favourites' Is there an other way to do it?
Thanks for your help