What is taking up my hard drive space?

My PS3 shows that I have 78 out of 120 gb of free space, I've add up all of my installed game data and it only comes out to 15 gb. I have about twenty themes and a couple wallpapers but I know those don't take up much space, I don't have any music or videos on my console and I only have one demo which is less than a gb of space. Does anybody know what is taking up so much space on hard drive?

I think the PS3's XMB uses up a chunk of the hardware space.

definitely check if you have demos or movies in your video section (which i did and took up 60GB!) then clear them to save space

demos, movies, game files depending how many files you have per game (ive erased the ones i don't paly), also big games that require instalation (mgs4 is the only one i can think of),

my ps3 is showing 1041mb of space shy of 18gigs. No Movies stored, No pictures, themes, no game other than GT5. Thats it, So my question is after determining that the file that shows what is stored on my ps3 says I have less than 3000mb stored - WHAT the heck is taking up nearly 17gigs of space??? I have looked and looked. We no longer have enough space to even install updates. Where can I find the hidden 17gigs and how do I remove them? Anyone? PLEASE. bwtchn

GT5 - the original install was somewhere in the 6-8GB range plus numerous updates!!

Check your Blu-Ray folder.

Game utility data can take up sizable space. I didn't know my friend played Skyrim on my ps3  and the ultility date was like 4 gigs O_o

The PS3 system itself reserves the good amount of the space and the hard-drive (when formatted) also reserves its share. It's how every HDD had been since the dawn of time.

My 320GB PS3 had something around 285 GB free.

A ghost is on your HDD taking away space. It's the Ghost of Playstation's past.:D