I Have a 13 inch Macbook Pro from early 2011. when I run things like "disk usage" on "MacKeeper", It tells me i'm using only 68Gb of space on my hard drive. According to "SystemInformation" i have somehow used 280 Gb. It tells me that I have 350 Gb used for backups. But i store all of my backups on a 500 Gb partition on a 2 Tb external hard drive through time machine.It says total disk usage is 280 Gb, and my max capacity is 320 Gb. How can i possibly have 350 Gb for backups? According to "DiskInventory X" I have used 109 Gb. Which is right? How can I know? Why is it even giving me conflicting numbers in the first place?