My HardDrive is Duplicating Items from another one...

Hi, I just installed Lion on one of my hard drives on my dual core tower and i wish to install applications on that hard drive with the OS on it but i dont have any space because somehow everything on my other hard drive was copied onto this one. The files on my Lion hard drive are applications, library, system and users. Users is what is taking up most of the space (inside it is applecomputer <with the home symbol> and a shared folder). Also, my time machine is turned off, so im not sure if that has anything to do with it. I tried deleting these files but it says they simply cannot be deleted.

Can anyone help me understand why this has happened and how I can get all my space back?

Thanks in advanced.