The Win 7 OS is one the first partition of C: and the flagged data drive is on the third partition (of 3). The second partition (not flagged for imaging) is used for other purposes.
When creating a system image, the OS checks the 1st partition of course, but also the third one.
My question is how can I tell which program (or whatever) causes the 3rd partition to be flagged for imaging which cannot be unchecked.