Propagate changes of disk layout / partitioning

Hi all,
I’m about to change the harddisk’s partitioning… this doesn’t seem to be a
hard task, but I wonder how to inform Windows about the changes. Is it
necessary to do so, or will the disk driver do it for me? What should I
especially care about when partitioning under windows using IoCtl? Can’t I
utilize the ftdisk services microsoft provides?
Regards, Tobias