Using fdisk

Ok i finally got a router so now i can install gentoo.... how can i use cfdisk or fdisk and make SURE i don't erase windows...?
sorry su root i think im still confused

edit: preferably cfdisk since i think you can see more stuff in there.
edit2: umm my disk is now nfts.... i hope thats ok...

Cfdisk is pretty straightforward. Anyone who understands partitioning should understand it. So if you have trouble with it... read a partitioning guide.

ok, well i havent seen it yet.... and about nfts... linux can't write to that, correct? so what do i need to do about that.

This may help some...