Follow these steps to determine how much data you have stored in your Network drive (T: U; or V: drive):
Browse to the drive you want to examine using Windows Explorer, or by starting at "My Computer."
Once you are viewing the contents of the drive, press CTRL-A to select all the items (or click Edit, then Select All in the menu). When all the items are highlighted, right-click on any item, then choose Properties. A new window will appear, telling you how many folders and files you have, and how much space they occupy.