D3D Score: The score that the Windows Experience Index gives to your computer's ability to replicate 3D images.

default printer: The primary printer that Windows uses automatically.

defrag; defragment: The process that your computer uses to rearrange the pieces of files and applications on your hard drive so that they are positioned next to each other on the drive, improving performance.

desktop: Windows 7’s main screen that shows your program icons, the Start button, and the taskbar.

desktop theme: A collection of settings that control the appearance and behavior of the various appearance settings in Windows.

Details pane: A small strip along the bottom of every folder that lists details about the item you’re currently viewing.

Device Manager: A Windows tool that shows you the status of all the hardware elements on your PC.

Device Stage: Windows 7 uses the Device Stage to gather all the information about installed devices into one central hub.

Digital ID: Digital IDs are certificates that you can use to verify the identity of the person with whom you’re communicating.

DNS Server: A computer that translates Internet addresses you can understand, such as www.dummies.com, into addresses that the Internet can understand, such as

double-click rate: The speed at which you click your mouse button twice. This rate is set in the Mouse Properties dialog box.

download: To copy data (usually an entire file) from a main source to a peripheral device.

DPI scaling: A Windows 7 feature that can make a system-wide change to the size of fonts and icons.

drag: To click and hold a mouse button while moving the mouse.

drop: To place an item on the desktop or in a window, after dragging it, by releasing the mouse button.

DVI; Digital Visual Interface: The standard connection method for certain types of video display, such as LCD monitors.

DVI-to-VGA adapter: An adapter that allows you to connect an older monitor to a newer computer or vice versa.