than cfdisk and make one big, bootable partition, minimum 3GB and one small, swap, 400MB. Write partition table to hdd, reboot and start installation - click on monitor icon, type su + Enter, than knx2hd, than Start installation.
If you did all this steps it is strange that you need to format swap partition. This is done during instalation proces. And if you did all things well, reboot, take CD out and you will have Knoppix runing from hdd.