thanks for your time.
in the end I formated new drive in external. Because I had the problem of going back to Vista with thinkpad's win 7 upgrade, I felt it less a hassle to clean install. I switched drives with new one in x200, then did custom partition pulled in previous 500gb drive's system sizes, and left remainder for my data.
On previous upgrade to seagate's hybrid XT I had problems with 'genuine' windows 7 registration. So I fixed this with the download below. All going well now.
The common cause for these mismatches is a faulty Intel Rapid Storage Tech driver
Download and install the latest version from....http://downloadcenter.intel.com/Detail_ ... iid=dc_rss