Could you please supply some more information. What type of install is this? A new install of Suse, with no other operating system on the disk? With another operating system on the disk? Is there any disk space not allocated to a operating system?
From what little information you provided, it sounds like the entire disk is allocated to another operating system. Is this the case?
Basically what needs to be done, is free space large enough for Suse neeeds to be made. The install process will give you options to 1. partition the disk(s) as required, and 2. format the new partitions.
Please include some information on the disk hardware, how large is the disk? free space etc.