D:\ partion does`t open,, any body help

Hi n Hello

i wanted to ask that my laptop partion which are apprantely C:\ and D:\.

one of my partion which is D:\ does not open by double clicking it, whenever i double click it the the dialouge box opens asking me to choose a program to open the "file" with, both has the NTFS partion system, and windows is installed on c:\..

but d:\drive is accessable by other options such as through folder option in windows exlorer and by right clicking and exploring the start button of windows.

does your laptop have 2 harddrives if not theres not much point in 2 partitions