单项选择题 Users in an office routinely work with large graphics files. Which of the following preventivemaintenance tools can assist in maintaining system performance?（）

单项选择题 A user reports that their touchpad no longer works on their laptop. Which of the following is the FIRST troubleshooting step?（）

单项选择题 A user reports that their hard drive has failed and needs to be replaced. Which of the following should the technician do FIRST?（）