I'm on a Mac and Bootcamp simply says it's unable to rearrange the space. I've researched the error and there are a few solutions, but most involve tinkering with the system in a way I'm not comfortable with (I can navigate Command Prompt in Windows, but Terminal in Mac is a whole nother story) or using pay programs to defrag my macbook. Anyway, I'll probably give it one more go next time I'm home and I have my install discs handy.

edit: of all things that have been preventing me from partitioning my hard drive, it appears it was my copy of the Star Wars Holiday Special. Not sure why my computer can't move the ISO, but hey. Ended up using this guide to diagnose my problems.