单项选择题 You run Windows Defender on your computer and receive the following warning message: "Windows Defender Definitions haven’t been updated." You need to ensure that Windows Defender definition files are updated. What should you do?（）

单项选择题 You need to identify if malware is causing performance issues on your computer. What should you do?（）

单项选择题 You have a computer that runs Windows Vista. You need to configure your computer so that you can interact with your desktop when you are prompted for user account control permissions. What should you do?（）