Hi, thanks for the reply!
No, that article seems to deal with reclaiming space by Mac from the VM, which is not my issue.
I have large files and directories in Windows 7 that I deleted, so it bypassed the recycle bin/ trash can and therefore, my secure deletion software. My software can securely "wipe" free space (using three pass method, for example.). Because the VM uses a variable partition, I'm not sure how to clean the Windows free space. I was supprised that I couldn't find anything in forum or on web, it can't be that uncommon of an issue for VM users. Thx!