Hi pcarey1, it is recommended to install the boot drive in the Intel® Z77 Express Chipset in RAID mode and reinstall the operating system in such configuration because it will allow Intel® Rapid Storage Technology to work properly. You may try other workarounds to avoid reinstalling the operating system but we cannot guarantee the results.
When you are about to create the RAID 1 array, go to Intel® Rapid Storage Technology software in Windows* and do it from there as indicated in the user guide, pages 30-33; this way you will keep the data from one of the drives. If you create the RAID 1 array from the Intel® RAID Option ROM (Ctrl+I) the data will be deleted.