I've only used it the one time when my hard drive was giving access errors and clicking loudly... I quickly google'd and found that program and successfully was able to get my system copied over (it's my main development laptop, would have been screwed bigtime!).
After that I haven't used it, so I don't really remember how exactly I did it. It was the middle of the night, and I woke up to a blue screen and clicking noises, so I did this all half asleep

By the time I got up in the morning, I crossed my fingers, swapped the drive, and still had to use the Windows 7 DVD to "recover startup options" or something like that, but after that, it has worked every since.