Windows 2000 IDE drive partition size

I am building a home system. I just bought an 80Gb IDE drive. I am installing Windows 2K. During the install Windows sees the drive as a 57GB unpartition space and a seperate 17Gb unpartition space. What knowledge am I missing? Why won’t it see the entire drive as a hole 80Gb unpartition space. Is there a way to correct this?