Need to Completely Erase Hard Drive ( start fresh) On a Mac With Limited Priveleges

I have a mac I received from school that has limited privileges on it. I need to erase this computer so it can be like it was the first time it was turned on. Thanks in advance. By the way it is a new 13inch macbook Mac Os x 10.5.7

 

Well, I was once faculty, and I don't understand your question.

However, if you have the 10.5.7 disc, it may allow you to change passwords. If you have a 10.5.7 disc, you can wipe the computer clean and re-install 10.5.7. Often Apple discs won't allow you to do this, especially if you're trying to install an older version.

In this case, I should run Linux from a CD & format it; then install 10.5.7. However, because I've never done this, I refer you to the Apple Discussions on installing 10.5.

 

http://support.apple.com/kb/HT1545

As long as you have the original restore discs or a later version (Snow Leopard retail disc), you shouldn't have a problem.

Need the restore media reissued? call 800-APL-CARE and they can order you a set for ~$30.

 

Though I'm still unsure of the question, I've given it some thought. Bass_Hit's suggestion may well give you the backup media you need. However, if the Mac came from a very good university, the local administrator likely bought a license and copied a gadzillion onto identical machines. Now you can't get your discs. You would likely have to buy 10.6, which may not access your drive at all (see nightmare scenario below).

My laptops were kept physically secure, so I'm unfamiliar with Mac's latest security mechanisms, such as encrypting virtual memory.

A dumpster gave me a Windows laptop. It stored material in a hidden partition, accessible by password (or someone with minimal knowledge). My solution was easy: use Windows & BitTorrent to download & burn an internet install disk, then use it to wipe everything & install Debian. You might think Macs would be this easy.

Fred, 'the computer guy' was the administrator, not me

You likely don't have a registered disk: only Fred does. Ask him to change your password. Otherwise, on earlier MacOSX, one could boot in single user mode, using a key combination. Then, if it allowed you knowledge of the short users names, you could become the administrator (sudo fred, or whomever), and change 'your' password. This doesn't require the original discs. It's well documented. 'Fred' will also have a 'KeyChain' in his home directory. Better to erase that.

File Vault

If you have encrypted your home directory with a separate password, good luck. decrypt it and back it up first. Apple seems to think an encrypted file, subdirectory, or partition will be erased with a new partitioning.

Peas & Carrots

However, I've found - for a Unix - MacOSX isn't very portable, not even from release to release. When downgrading, erase using a disc at least as old as the installed OS, then install the version the hardware came with and upgrade it to the release it came with. (The release & hardware go together 'like peas & carrots'.)

The Nightmare Scenario

Mac changed its default partitioning scheme with 10.4.6 (I think). It remained APM (Apple Partition Map) on older PPC Macs, and became Intel's GUID on Intel Macs and newer PPC Macs; at least, I think so. Leopard 10.5, won't install on disks partitioned APM. Perhaps this is your problem.

Administrators sometimes upgraded 'hot-rodded' machines by following this kludge:

Convert a Drive from APM to GUID Partition Map
http://www.macosxhints.com/article.php?story=2007102511133285

BTW, should you now want to make that external drive a repair drive for both your Intel and PPC Macs, Apple suggests how:

Create an external drive for 10.5 on both PPC & Intel
http://support.apple.com/kb/HT2595

Note that, if you aren't confused now, there is worse. What Linux would do with the above proprietary-sounding partition, I've no idea. GNOME & KDE now support at least 2D-hardware acceleration. But, it further upon the BIOS, the MBR, & all sorts of things no longer needed on GUID Macs. I don't want to know about them. You may:

Myths & Facts about Intel Macs
http://refit.sourceforge.net/myths/

The above is useful if you want to dual-boot a Linux distribution. Though its file system is ext3 or ext4, it will read & write HFS+.

Final Straw

If you've had it and want to buy a new drive rather than continue, there is a dangerous option. Most ATA drives will 'self destruct', sort of like Mr Phelps's tape, so government-classified data can be wiped to the satisfaction of the DoD. Until recently, only the DOS 'HDDerase' would trigger the countdown. Now, however, you can do it with 'hdparm' on a Linux LiveCD. Drives are usually ready to re-partition afterward, but nothing in this world is guaranteed.

How to Nuke your ATA Drive
http://ata.wiki.kernel.org/index.php/ATA_Secure_Erase

Good luck, Mr Phelps.
Gneiss1 will deny any knowledge of mistakes above.