Use some hardrive software for configuration. I use "maxblast 5.0" a free download off seagate's or maxtor's website. It will give you configuration options. Decide how big you want each partition to be then set one as master or primary, the other one as secondary. The operating system you choose will let the software give you the maximum size partition your version of windows and motherboard bios can handle. It's easy to set up, and you can clone another drive to a partition if desired, saving lots of time.