Migrate Easy 7.0 red 'C'

I'm trying to clone a hard drive with 2 partitions on it, C: and D:. Also, I need to resize the c: partition on the new hard drive. Migrate Easy should be able to do this by choosing to migrate manually. On the screen where I can adjust the new partition sizes, I noticed a red 'C' over the yellow bar for the C: partition. I also noticed that I can't change the new partitions size. The D: partition doesn't have this red 'C', and I was able to change the partition on that one. In fact, I had to because I needed to make room for the C: Partition. I made enough unallocated space to expand the C: partition, but all that lets me do is move around the C: partition. What's going on here?

Extra notes:
The origin drive is not the drive that the computer used to boot up.

As an experiment, I tried to clone the drive that computer did boot up from and saw that the red 'C' is also there too on the partition where the computer boots up from.

I'm using Windows XP Professional.


If you've seen this red 'C' please tell me what it means and also how do I get around it.