If your Mac OS install disc lost is lost, you lost your password and the one thing that you are most afraid of losing is your data, this article is the answer to all the questions on your mind. Not only will you be able to figure out how you can reset the password, but will also get your data back.
Help - I've Lost My Password!
The easiest way to recover your password is to use the install discs that came with your Macintosh computer. Not only is it the easiest way, it also happens to be the quickest if you're slight on the technologically challenged side. I'll invoke a reversal of Occam's Razor here and suggest you do either of the following:
1. Look for your Mac install discs.
2. Borrow someone else's Mac OS X install discs.
If you've spent all weekend doing the former then it is time to spend some effort doing the latter. If possible get hold of the box that you Mac shipped in. The reason we need the box is to figure out what version the install discs that came with your computer were and that is usually mentioned on the box.
Of course, if you already remember that information then that is better. You'll need to find a friend or a colleague who has the same install discs as you had. The quickest way to getting this info? Put out a tweet and update your FaceBook status to say that. Some one should step up. Once you get your hands on one of this discs, follow the steps that are outlined here and you should be on your way to data recovery. By the way, even though the Apple Doc might say that the steps are for OS X.4, they work up to the latest version of the Mac OS.
No Luck With the Discs?
Even though all your FB friends might like you enough, there is a chance that you might not find the discs that you're looking for. The second best way to get your hands on your lost password is to figure out the Target Disk mode on your Mac. You will need another Mac to do so and will need to go through a couple of steps to get the Target Disk set up right.
Thankfully, the Intel Macs can run Target Disk off of any old USB hard drive that you've got lying around. One of my cousins who is a certified Apple computer repair tech for a big corporation carries around a Target Disk installed on a USB thumb/pen drive on his keychain all the time. If you have an older Macintosh, specifically one that has the PowerPC processors instead of the Intel ones, then you will need to get your hands on a FireWire disk to make the password recovery process possible.
Click here to read Apple's official info on getting the Target Disk mode running for your Mac.
Single User Mode
If the Target Disk fails, here is what you need to do in order to reset your password. Do make not of the fact that you will lose all your Keychain Access data, but it is a small price to pay for getting all your data back.
1. Boot into single user mode (press Command-S at power on)
2. Type fsck -fy
3. Type mount -uw /
4. Type launchctl load /System/Library/LaunchDaemons/com.apple.DirectoryServices.plist
5. Type dscl . -passwd /Users/[username] [password], replacing [username] with the targeted user and [password] with the desired password.
The above steps will allow you to reset your password. Let me know how it went in the comments below!