Primary Partition

I am trying to install Win XP on my new Dell with a Vista OS. I partitioned my hard drive but can't get it to become a primary. There are already 3 primary partitions. One is Vista(C), one is recovery(D) and the other is labeled EISA config.(no drive letter) and we can't change that one. Do you know if we can change the recovery partition or the EISA to something other then primary? The recovery partition is something that DELL installed at factory and they don't recommend it being changed.

Thanks for your help.