Hi, I am not new to this forum but I did happen to forget my password and email from awhile back. Anyways I'm currently on my Mid 2010 1TB iMac (21.5) and I have installed Mountain Lion. So before doing so I wiped my computer clean and then installed 10.8. Everything has ran fine and everything is all good but I do have a general question. I know my way around my computer and I consider my self to generally know a fair amount about Macs and there operating system, but not too much on hardware. I did all that about 3 weeks ago and since then everything has been fine, but today I installed some new apps from the Appstore, like Memory Cleaner, and some little apps, and as im going through the apps it said i've used 500gb of my harddrive already. I haven't downloaded much of anything at all though so it really surprised me. I checked my computer and looked at the storage and it was true, it said in the "other" tab that 500gb was already used. How is this possible? How can I fix this? Thanks! Tl;dr 1Tb harddrive says 500Gb is being used. How do I see what is being used/fix it? Thanks! There is a picture attached with what I am seeing. Edit: Whoa now it jumped up to 650 being used! Whats going on!?