To Delete: Go to the start menu or All Programs right-click the file name, and then select Delete. This will send the files to the Recycle Bin which is a good thing in case you decide you want to recover them. To free space on your computer, you’ll need to empty the Recycle Bin from time to time. Go to the icon on your desktop and right click, then click Empty Recycle Bin
To Restore Your Computer to an Earlier Time: Go to the Start menu, click All Programs (or Program Files), click Accessories, and then click System Tools. Click System Restore, and then it will guide you through the rest of the steps.