hard drive / 2nd

I have put the second hard drive in, but Comp. does not recognize Disc Space … ?????? Do I need to format, { before Linking the Two together }, making second drive — D: ??? It is calling it D, but with No space… available !!!!!!!!!!!! Formatted with drop-down format, but only CREATED 101 MB…. Disc is 30 GB……… ??????????????? What do I need to do to get Comp. to acknowledge disc space ??????????????????????????
Thanks !!!!!!!
D.L.J.