Answer: Yes there is! Prodigy Mark Russinovich wrote the Windows counterpart of UNIX’s indispensable du command called, uhm, du: http://technet.microsoft.com/en-us/sysinternals/bb896651.aspx
Copy du.exe to %Windir%/System32. (The /usr/bin equivalent of Windows).
To obtain the size of top level subdirectories in a directory, with the largest on first in Bash@Linux, we type:
du --max-depth=1 | sort -r
The equivalent for Powershell@Windows would be:
du -q -l 1 | sort -descending
What I would really like to see is Mark’s du.exe be able to return directory sizes in well, “human readable formats”: KiB, MiB, GiB, TiB etc etc. In UNIX’s du, the argument -h does the job.