To reset your computer if you do not have a reset switch, select start, turn off computer and when the window opens, select reset. If the computer is frozen, and you cannot use CTRL+ALT+DEL, then hold in the power button for a few seconds until the computer shuts down. Wait about a minute or two before turning back on. If you need to restore your computer, select start, programs, accessories, system tools and restore. Follow the prompts on the screen to restore you computer to a previous time.