I recommend giving more space to the free/not partitioned portion of the hard drive. Sometimes the system does not allow to create a raid volume due to there is lack of space in a partition. Check this link for more information http://www.intel.com/support/chipsets/imsm/sb/CS-029494.htm
Thanks for your response Fred_Intel.Now that I look back at the original post that I realize I did a very poor job of describing the allocation and free space, so I am restating it here:100 Mb System/Reserved195.21 gb Boot/Windows50.65 gb Data585.84 gb Data99.61 gb free/not partitionedThis should clarify that there are 99.61 gigabytes of non-allocated space on the drive, so I think there should be enough available space. All, but the System/Reserved partition have a least 13 gb available.Also, today a message bubble popped up when I launched RST. I was not able copy the complete message before it disappeared, but started out as:Intel Rapid Storage TechnologyA disk is available to use that could improve... (and then it said something about performance).To me, this indicates that RST thinks it "should" be able to mirror the drive.
Well...after making several copies of my system, I used the WIN 7 Disk Management utility to shrink all 3 partitons by a at least 10 mg each and I took a step backwards. Now I no longer see the "Create" button using the same Admin account I was using previously.
I think the RST configuration must be pretty messed up and will probably just wait until I have time to perform a clean WIN7 install when I have more time.