well the standard dell hdd comes with 3 partitions. 1 partition is for the dell diagnostic module--you can use this partition only through the "FN" key or the F12 function. Another partition is the main partition that of which the OS is on. The last partition is a hidden partition so you won't find in your listings, because it is a backup partition so that if you have a virus or something like that you can just use a key function and restore the system to its original image (thus erasing all information). Standard Dell support doesn't support putting more than one os partitions...like linux and windows because its considered advanced configuration and well they do have a department for this but its fee based.. :\