Completely & Security Wipe Data From MacBook But Keep OS?
 

I have a Macbook Pro that was given to me by a company that I am doing some work for. Although they told me they were giving it to me, I was just told that it needs to be returned and they are sending me out a new one with updated software.

Whatever, no biggie, but... I've also been doing a lot of my adult site work on that as well have a lot of personal information stored.

What is the best solution to completely wipe everything off but keeping the OS and current software in tact? I was going to use one of those programs that erases the HDD like 47 times, but not sure how that works with a Mac

Usually when you erase a disk or volume, Disk Utility only erases the information used to access the files on the disk, not the actual files. Because of this, the erased files can be recovered.

If you want to erase the files so that they cannot be recovered, you can select security options to write zeros over the disk space. To make it more difficult to recover the files on the disk, you can specify doing this once, seven times, or 35 times. If you have a large disk, overwriting the free space several times can take a long time.

In Disk Utility, select the disk you want to erase and click Erase.
Specify a volume format and name for the disk.
Click Security Options and select the option you want to use. Click OK.
Click Erase.

What KRosh says and yes, you have to reinstall. Also note that on a .5 tb drive, the 101010 option took me about 15 hours. So do it before you go to bed ~2 centz