Windows updates installation not being tracked by VFD

Hey guys,

I am working on change block tacking using WDF based volume filter driver. The
project development is in final stage, we observed some files are not being
tracked by the volume filter driver. We can reproduce this issue only with the
help of windows update installation. I see some $MFT/$Bitmap/$Extend related
blocks are not being tracked during software installation.

Could you please help me out here to understand the probable reason behind this issue?
How software installation behaves differently at file system layer? Just for
information I have also handled the DISK_COPY IOCTL.

Thanks in advance :).

-Amit

Could any one please help me out here?