Also, this issue of not using anything outside the OS.
I cheated by using XP to get over the problem of W7 not being able to format over system files. So, drive C was greyed out for format. However, I used an MS product which I hope is not veering too far off the ideal.
I know that these partition programs work, it's just that I got the feeling they were somehow simulating the task with instructions lying about in hidden places. I recall coming to that conclusion, but not the exact reason.