Computer designers usually divide hard disks into a number of partitions to manage files and folders effectively. Partitions receive a drive letter so that operating systems can identify them. Usually, operating systems such as Windows 7 and Windows Vista are present on the C drive, but a multi-boot system can also have an operating system on the D drive. If you wish to see the contents inside the D drive, you can access it using Windows Explorer.
Open Windows Explorer. To do so, click the "Start" button on your Windows task bar and select the program labeled "Computer."
Right-click the icon labeled "Local Disk (D:)." If the D drive on your computer is an optical drive, the icon will be labeled something like "CD Drive (D:)" or "DVD Drive (D:)."
Click on the option labeled "Open" to view the contents inside the D drive.