Vladimir:

I make a littler more investigation in the problem and Microsoft said that the problem is and quote "

After consulting, I was told that WMI will internally use
GetDiskFreeSpace() API function. While GetDiskFreeSpace is processed by
CDFS, which is a read-only filesystem. So the return value of Free Space is
always 0.

To workaround your issue, we need to use Image Mastering API(IMAPI) to get
this done. I will spend some more time on IMAPI to resolve your issue.
"

Do you know what he is talking about? I don't