You can use the DirUse utility on the Windows NT Workstation Resource Kit CD to obtain disk space usage per folder. For more information about DirUse, type diruse /? at the command line, or see the Windows NT Resource Kit Tools Help for information about this utility.
This utility is useful to get the actual usage of space for compressed files and folders in NTFS volumes.
The format of the command is:
diruse [/s | /v] [/q:#] [/m | /k | /b] [/a] [/l] [/d] [/o] [/c] [/,] [/*] [dirs]
The option of interest for compressed folders and files is /c, which causes the display of compressed file or folder size instead of apparent size. For example, if your D drive is an NTFS volume, type diruse /s /m /c d: at the command prompt to get the disk space actually used (in MB) and number of files in each of the folders. To see compression information for an individual file, you can use My Computer or Windows NT Explorer, select the file, and select Properties from the File menu.