Ok, so I downloaded iATKOS v7, and I've been using these instructions. It sounded easy but five minutes into it and I'm already stuck. The "Pick Your Destination" window is blank, and that's when I realized I should ask for help instead of risking losing valuable data.

I currently have three hard drives, with two partitions each. Windows 7 RTM is my primary OS. I have Vista installed too, but I don't use it anymore so I don't care if I won't be able to boot into it again. The only reason why I keep it around is because I use the programs and data from that partition.

Here's a screenshot of my current hard drive setup:
http://imgur.com/yMziK.jpg

The guide I've been using seems helpful but it's not very detailed. I like to know why I'm entering these commands it mentions so I have an understanding of what I'm doing.

Given my situation, help is greatly appreciated.