This message was posted on behalf of Intel Corporation
Thank you for joining the Intel® Rapid Storage Technology Community. I am really sorry hear you are having issues with this matter.
Based on your description it seems like the two disk were included into a RAID 0 configuration, this reformatted the big size disk causing to lose all the information in it, and leaving the information from the small drive split between the two disks. In order to separate the two disks, I recommend accessing the Ctrl+I menu and set the disks to non-RAID. Make sure to back up your information first, and if you attempt to follow this recommendation Windows needs to be reinstalled.