单项选择题 Which of the following is the purpose of the sigverif.exe utility?（）

单项选择题 A technician is performing a memory upgrade by installing an additional 1GB stick of DDR RAM into a system. When the installation is complete, the computer shows 2GB of RAM at POST; however, it now indicates a lower speed setting for the memory. Which of the following is the MOST likely cause?（）

单项选择题 A user reports that they are unable to open any audio files. Yesterday, the user uninstalled third party music software. Which of the following is the MOST likely cause of the user’s error?（）