1TB HDD iMac question/help

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!?

simsaladimbamba said:

What is this "Other" in the storage tab? What is eating up my space? by theSeb

To find out, where you storage capacity is being used, you can use the following free applications:

• DiskInventory X
• OmniDiskSweeper
• JDisk Report
• GrandPerspective

Maybe try a combination of several, if you still can't find the "missing" capacity.

PS: Applications like MemoryCleaner are not needed, as Mac OS X takes care of memory management.

Mac OS X: Reading system memory usage in Activity Monitor​

Click to expand...

Thank you for the links!
So I used Disk Inv. X, and it wasn't much help. I now have downloaded JDiskReport and it gave me the same information. I don't really have any idea what it going on. Is there any other possibilites? Ill attach a picture of what my Disk Utility is telling me if that helps.

simsaladimbamba said:

Have you read the first link yet? It tells you what "Other" is and how it can be disabled. Disk Utility will not help.

Click to expand...

I did not see the first link, I thought it was an ad. I am looking at it now. I have also restarted my computer and it is all normal now.

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simsaladimbamba said:

Have you read the first link yet? It tells you what "Other" is and how it can be disabled. Disk Utility will not help.

Click to expand...

Thank you, I have followed those Instructions and got a nice view of whats there, however I got to see the real "other" I do not know where the 600 gb being used came from, but I may have an idea maybe. If I run full system virus checks or anything like that matter would it crank up the "other" in my Hdd until I restart my computer?

simsaladimbamba said:

It is not a virus nor is it malware. It is Time Machine doing local backups.

Currently there are zero viruses affecting Mac OS X in public circulation, but there are other kinds of malware existing, that can infect your Mac.
To learn more about malware in Mac OS X and what steps can be taken to protect yourself, read the following F.A.Q.:

Mac Virus/Malware Info by GGJstudios​

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I have time machine currently disabled and haven't used it at all yet. Is that still the reason?