I have 250GB and I know that that really means about 230GB or so. However, I'm not even close to filling that up if I go down and check out the files - it only adds up to about 70GB. My user file takes up the most at 54GB. I used Disk Inventory X and found out that there is a hidden Volumes folder that accounts for 139GB of memory (that's where the lost memory is) and it seems to be the exact files that I backed up to my Western Digital xhard drive. Why are they there and how do I get rid of them???? Please help!