单项选择题 You need to back up the existing data on a computer before you install a new application. You also need to ensure that you are able to recover individual user files that are replaced or deleted during the installation. What should you do?（）

单项选择题 You need to back up the existing data on a computer before you install a new application. You also need to ensure that you are able to recover individual user files that are replaced or deleted during the installation. What should you do?（）

单项选择题 You have a computer that runs Windows Vista. You need to collect performance data on your computer for a period of four weeks. The performance data must include CPU utilization, memory utilization, and disk utilization. What should you do?（）