Treesize is a powerful, flexible and free harddisk space manager for Microsoft Window 2000/XP/Vista. You can monitor the size of the folder in your harddisk either is the unit of KB, MB, or GB.
Besides that, you may view the detail in term of the number of files, the last access date, the file owner and also the permissions. So from here you know that which folder in your harddisk is actually taken up most of the space.
You may also export or print out the report get from the Treesize to help you to do the housekeeping in your drive to save space.
Click here to View on TreeSize