I have really vital documents that have been uploaded onto my computer not to mention the fact that I have used my computer for buys and my name and other vital info is on there. Can anyone please tell me, in detail, how I can permanently erase EVERYTHING that is on my Apple Macbook hard drive and on the computer itself. Can you tell me how I can do it for free? (without purchasing software or anything like that). Thank you, I really appreciate all the helpful answers.

First, this question has already been answered on here and honestly recently too:http://answers.yahoo.com/question/index;…
It’s real simple, here’s the answer:
Here is what you want to do (I just did the same thing)
First : Make SURE you have your OS install disks (these came with your computer). If you don’t, skip past my first directions. My first directions are the best and safest way to do it.
Second: 1. Insert the Mac OS X CD.
2. Restart the computer.
3. Immediately after the startup sound, press and hold the “C” key to start up from CD.
4. When the Installer screen appears, do not click Continue. Instead, choose Installer > Open Disk Utilities.
5. Select the hard drive to erase.
6. Click the Erase tab.
7. Select the volume format from the Volume Format pop-up menu.
8. Click Options.
9. Select the checkbox for “Zero all data”.
10. Click OK.
11. Click Erase.
Also, if you have an external hard drive – you can bot from that (when turning on your computer hold down Alt and when two hard drives appear click the copy) and boot Disk Utlity from that and follow the same directions.
Apple doesn’t give out free OS disks but you can call and see if they will send you your OS disks for a smaller fee than buying Leopard. (http://www.apple.com/support/contact/pho…
Hopefully you have your disks.
(http://forums.macrumors.com/showthread.p… You can also try and download the drivers in a torrent – not sure how simple this would be to find / download.
I suggest calling apple (support link above) if you don’t have your disks.
After you erase – you just insert the first disk and it will guide you through the process. It does require you place in your name – or you can just wait for the other person and tell them to install it. I installed with my name and address as I had to place other applications on when I sold it so they could see it in action.
Excellent luck selling – and any other questions just contact me through Yahoo! – I’ll try and do my best to help.