This is not exact, but very close - use following ioctl commands and multiply (result is in bytes):
IO_IOCTL_LAST_CLUSTER
IO_IOCTL_GET_CLUSTER_SIZE
PetrM
This is not exact, but very close - use following ioctl commands and multiply (result is in bytes):
IO_IOCTL_LAST_CLUSTER
IO_IOCTL_GET_CLUSTER_SIZE
PetrM