Mac Mini reset issues

[Cherokee92]

I got an old Mac Mini from a friend, i think they got it from their workplace after they upgraded to new computers. But it's still locked, and I've tried everything. I can't do much not even knowing the build version of OS it has (I can only assume 10.5 or 10.6 due to when it was originally abandoned) I tried burning an OS disk and booting to it, but the drive refuses to see the disk at all. I tired booting into recovery mode, but the mac doesn't respond and continues booting (So it isn't OS X Lion). I've been trying to reset it in the command prompt (Single-User) but again, nothing as it either says file not found or unknown command. I noticed with the videos showing how to do this the command line is something like :/ Root# Where mine shows as localhost:/ root#, clue maybe? It was at an elementary school so I'm sure it was networked and has protection on it. I'm at a loss and have no experience with Macs, all of my other computers are Windows. Help please!

 

[gtstricky]

try these steps:
http://www.macyourself.com/2009/08/03/how-to-reset-your-mac-os-x-password-without-an-installer-disc/

 

[Cherokee92]

Making a new account worked, I now know it's running 10.4. I don't get why the reset steps for 10.4 didn't work then... Are the commands case sensitive?

Thanks for the help!