单项选择题 A system powers on, begins POST, displays the BIOS version information and then hangs with the error message ‘Error loading operating system’. Which of the following is MOST likely the cause of this issue? （）

单项选择题 A technician replaced a floppy drive and now the front indicator light is consistently illuminated.Which of the following is the cause for this?（）

单项选择题 A technician installed a new motherboard in a workstation. Which of the following describes theBEST steps for a proper installation?（）