Thread: GetDiskFreeSpace Windows API fails on windows 2000

Hi All,
I need to calculate the cluster size using my program.
Windows provides API - GetDiskFreeSpace, to serve the purpose.
But the API fails on windows 2000 host giving the following error-
--------------------
ERROR_DIR_NOT_ROOT 144 (0x90) :The directory is not a subdirectory of the root directory.
--------------------
The same program runs successfully on windows 2003 and above.

Does anyone knows the solution of this problem?