You start by clicking on the file list and select "New Task" that brings up a dialog box. You want to select the second Task "Files on folder", you want to erase the files inside of the folder so Tick subfolders. You see the big square to the right of the slot, click on it. It brings up a dialog box, just click "My Computer" and navigate to the folder, when you select the file you click "OK" and "OK" again on the Task Properties dialog box and it will appear on the white part of the user interface.
Having neither the time nor the skill to "find" all the multiple folders (both permanent and temporary) that Windows, IE, FireFox and Opera (go through all the settings on any browser you use and make sure it's set to delete all temp files and personal info upon exit, to start with, and that it doesn't keep any "History' lists for more than a day) "store" things in, I pretty much rely on keeping updated copies of :
CleanCache - http://www.buttuglysoftware.com/ (Please note - you've got to d/l and install the .Net framework for CleanCache to function properly - if you don't feel like doing that, skip to the next one).