How to fix a mis-named hard drive?

I have a 2006 white 21" iMac and I was rebooting the computer (holding the option button to select the boot drive) and my internal hard drive wasn't there. So I went into tech tool pro and the hard drive itself shows up but its subset is greyed out and it is named "disk0s2" (its normally called "Hard drive") which from what I can surmise is the default name for the internal drive. If I try to repair the drive it errors out after the very first step (the HFS check). I have removed all of the vital files from the drive and have run all of the repair programs within tech tool and the drive will still not mount. I have been messing around in terminal (which I have NEVER used before) with no luck and at this point I am just looking to revive the computer. I have tried to run a clean install but it requires you to select the target drive which I cannot do (the same thing with Time Machine). In terminal disk utility the apple HFS has no name the identifier is "disk0s2" are there any terminal commands that I can use to name/rename the hard drive? Any possible solutions are welcome and thanks in advance for your assistance.