Firstly the Linux directory structure does not work like windows.
There are NO drives by default.The OS and the other things all come under one directory-ROOT represented by "/ "
Here is how the Linux Directory Structure is-
The /Home is similar to your My Documents+My Computer
Well,Though the structure is not Drive-based,like windows,you can create partitions(drives) similar to windows(But they wont be named C: or D:...You may label them as seen in the screenshot below or they will be named New Volume1/2/3etc).They are treated as an external media(somewhat like a usb).In linux,anything other than the what is under "/ " by default is an outsider(and so are the partitions/drives).
Here is how the drives will look if you hve them-
The Devices part you see in the upper left corner are the drives(the
Eject arrow shows how they are treated or considered as external devices).
While what you see in the remaining browser is the /Home" directory.