Did you actually bother to follow the link I gave you?
This is a well documented problem with the FC2 installer. It's easy to avoid at installation time by passing the installer some information about the disk geometry. This is why you need cfdisk.
cfdisk must be run as root. You're probably trying to run it as a normal user, which is why you get the 'command not found' message: the program is not in your path. Either do `su -` and run it, or do `/sbin/cfdisk` then enter your root password.