problems addign 3rd party source to VS

hallo - using VS9 at my new job, and i've been having nothing but trouble trying to add 3rd party source to my solutions.

in particular, this one just does not want to compile:

SourceForge.net: An AES/rijndael encryption library: An AES/rijndael encryption library

i'm guessing it's something to do with my project options or some such...if someone can manage to get it to compile, please let me know how you went about adding it to your solution/project. thanks much!