Hi Kas,
for managing partitions windows 7 does have it's own tool, this can be found via Control panel, admin tools, computer management, storage tools and then disk management. All you need to do is right click on the partition/drive you'd like to change.
If that isn't what your after then this free application may help some:
EaseUS Partition Master Home Edition - CNET Download.com
Now back to your original issue. Could you look at this screen snip I took of the above Canon website and tell me which application you downloaded?
Link Removed
Once I know which app we are dealing with I can go on to help further..