Installing Jessie on a computer that current has Windows 7 on it

[Paul E Condon <pecondon@mesanetworks.net>]

I have NO interest in dual boot. I simply want to wipe the disk and install
Jessie. I have last weeks weekly build of debian-testing-i3k6-xfce-CD-1.iso.
I starts nicely like I have seen many times before, but when I get to
partitoning the HD there is trouble. It won't overwrite the NTFS partitions
that contain Windows 7. I think I have read about this and there is some
special trick, but I can't find it. Please, someone. Help. Point me to the
directions.

-- 
Paul E Condon           
pecondon@mesanetworks.net