Merge two partition between two RAID system

Hi All ,

I have one machine HP ML 350 G3 running Windows 2003 as a fileserver,
two RAID systems (Hardware RAID ):
– RAID 1 , 2 HDD , 2 Partition ( C & D )
– RAID 5 , 4 HDD , 1 partition ( E )

Question is..can i merge the partition D and E ?

your help would be appreciated..thx