I'm not sure if i'm posting in the proper place so forgive me if this should go elsewhere.

I'm evaluating hard disk encryption software for the University that I work for and there is one that I really like, Pointsec for PC.  I've encrypted the disk on a testing laptop and gone over it with a Helix CD and i wasn't able to do anything, which is to be expected.

The question is, how could I verify that things are actually encrypted?  I know, this is a reputable product with certifications from everyone under the sun and I'm sure they're not cheating me, but hacking is about curiosity and learning new things.  How do I know that the software really encrypts the disk and doesn't just mess with the partition table or make some modifications to the MBR while leaving all of my precious data in the clear?  What would it take (other than independent certification) to satisfy you that the data was encrypted?  How would you verify it?

Thanks!