Can only see 1.6 tb with an 4 x 4tb raid 0

You need to install the raid driver in Windows. For Intel, go to their downloads website and get the latest version of the Intel Rapid Storage Technology drivers for your system

Assuming Windows 7 64-Bit, Given the information provided, most likely you are either running into a configuration problem or a limitation of older SATA chipsets.
1. Take a look at your RAID option-rom on the BIOS. This will give the base information that is being passed into the OS. If this doesn't properly say RAID 0 4x4TB = 14.5, etc, etc, then your resolution will be in reconfiguring the drives. 2. Right-Click my computer and click manage. Go to Disk Management. This will show physical drives (your big RAID 0...I know logically physical...), then the logical partitions on them, see what shows up in there. If it shows as a big drive in there you just need to reformat from inside windows. 3. If you are running into major snags at every turn, look into buying a Sata III chipset expansion card like this one from amazon http://www.amazon.com/gp/product/B009LIPHNC?tag=anan06-20

Disclaimer: RAID-0 gives you ZERO redundancy and multiple times the amount of Risk failure-wise. If just one of your disks fail, you'll lose all 14.5 TB of data. If I had 14.5 TB of storage, I would use RAID 5 or something to give myself a little redundancy.