Sometimes back we talked on how to find biggest folder of file size in windows but its bit of manual process and needs to be done when you really want to drill down whats occupying space on your hard disk. Not for vista but at least for the previous version there is a solution, called as Folder Size, available which allows you to display folder sizes right into your windows explorer detail view.
Folder Size caches the sizes of all folders viewed in Explorer. The service monitors folders for changes and updates the cache in the background. That sounds good as it doesn’t get your windows slow. This service installs as a service and wait for sometime for the result to appear.
Once its done you should be able to see the folder size which is generally empty in your windows detailed view of files and folders. Download Folder size.
As said it doesn’t work on Windows Vista but you can try this small hack to find it easily by using operators in search box.