http://bugs.winehq.org/show_bug.cgi?id=12218
--- Comment #8 from Wim Lewis wiml@hhhh.org 2009-10-11 01:18:45 --- FWIW, I wrote a dummy implementation of IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS to see how the installer would react. It seems to make many more syscalls after IOCTL_VOLUME_GET_VOLUME_DISK_EXTENTS if it succeeds than it does if it fails, but it still leaves the required/difference columns blank.