A co-worker uses a gadget from the Windows Sidebar feature on their computer. You examine your computer and find that the gadget is not on the list of available gadgets. You need to add this gadget to the Windows Sidebar feature on your computer. What should you do？（）

A. Download and install the gadget file.
B. Download the gadget file and copy the file to C：\Windows\System32.
C. Instruct the co-worker to send the gadget file via e-mail and copy the file to C：\Program Files.
D. Instruct the co-worker to send the gadget file via e-mail. Drag and drop the gadget file to the Windows Sidebar feature.