"EISA Configuration" partition

That sounds like an OEM utility or recovery partition. You might be able to get rid of it using the disk tools in UBCD4WIN, Reatogo, BartPE, etc. You could then create a new, small partition out of it for your own use or you could image your machine, wipe out both partitions, create one partition from all the drive space, and retore your machine from the image.