Windows 7: Win 7 vs External Hard Drives

I have a HP Pavillon laptop with Win 7 Home Edition.
I am a video (old movie) nut (approx. 5 tb).
The movies are stored in a Raidon GR5630-3B3 chasis.
The array holds (4) 2tb WD (WCAZA...) hard drives.
The hard drives are configured Individually ( F,G,H,I). "UNPROTECTED"
i replaced the (4) 2 tb drives with (4) 3tb WD (WCAWZ) hard drives.
This was to establish a Raid 5 configuration to "PROTECT" my data.
Problems:
#1 when installed the new array, disk manager was gracious enough to partition
my new configured (8.19tb) hard drive into 2tb allocated and 6tb unallocated.
#2 When i went to transfer the data from the old (2tb) hard drives to the new,
Win 7 disk manager would not recognize the old hard drives,
What I though was a relatively simple process has turned into a nightmare.
regards