hi! I just blew up my mbr, and I want to use knoppix to reinstall lilo. but I get loads of permission denied and unable to open-errors. I can mount /dev/hda7, (my reiserfs linux root partition) but cant change hda's mbr... help??? how can I clean the mbr, and install a new one, using knoppix?

btw: using lilo, it tells me: Fatal: unable to open /dev/hda: permission denied.
all disks are set writable...

please help!