bdi install

i get this message from the bdi cd .
[ you must assign a root (/) partition to a linux native partion
(ext2) for the install to proceed) I am new to this thing so please
be kind . and any thoughts of things to come in the install.i've
went through the manual but did not see anything regarding this and
also did a search to see if anyone else on this site had this thing
before.i have a dedicated HD for this install.

thank you for your help.

Richard