Password, is there some way to retrieve my System Preferences password?

Question

Is there some way to retrieve my password ysed to login and install? I have lost my sytem password...

Answer 1

Incidentally, I found this:
About Apple Hardware Test
Apple Hardware Test diagnoses and detects problems with your computer's internal hardware components, such as the logic board, memory, and wireless components. It does not check external hardware components, such as USB or FireWire, or non-Apple devices, such as PCI cards from other vendors, nor does it check for operating system (Mac OS X) or software-related problems, such as application or extension conflicts.
You may be able to start up your computer with Apple Hardware Test even if the machine will not start up under the Mac OS X.
Using Apple Hardware Test
Before using Apple Hardware Test, disconnect all external devices with the exception of keyboard, mouse, display, and speakers. You should also disconnect the Ethernet network cable. If you are using the MacBook Air, you may need to connect the MacBook Air SuperDrive. Print out these instructions before proceeding with the following steps.
1. Restart your computer, holding down the “D” key while the computer restarts.
2. When the Apple Hardware Test language chooser screen appears, select the language appropriate for your locale, and press the Return key or click on the right arrow button.
3. If your computer is not supported by this version of Apple Hardware Test, an error dialog will be displayed. You should Shut Down the computer, locate the correct Mac OS X installation DVD containing Apple Hardware Test for this computer, and repeat the above steps.
4. If your computer does not restart to Apple Hardware Test:
    a) Restart your computer with the Mac OS X installation DVD containing Apple Hardware Test. This should be the same DVD this document resides on. Hold down the “D” key while the computer restarts.
    b) If your Mac has a Firmware Password enabled you need to disable it first using the Firmware Password Utility when booted from the Mac OS X installation DVD.
5. When the Apple Hardware Test main screen appears, follow the onscreen instructions.
Advice about using Apple Hardware Test
If Apple Hardware Test does not detect a hardware failure, the problem may be software related.
If Apple Hardware Test detects a problem, it displays an error code. Make a note of the error code before pursuing support options.
Alternatively if you are able to startup your computer from Mac OS X, you will be able to retrieve the error code, and optionally send this information to Apple, using the System Profiler utility application (which can be launched from the "About This Mac" dialog).
If your computer has more than the minimum configuration of RAM, the Extended Test may take significantly more time than indicated on the screen. Your computer can use memory modules or DIMMs even when the Power On Self-Test, which runs when the machine is turned on, detects part of a module as being bad. When you start up your computer, Apple Hardware Test reports failed memory modules in the Hardware Tests panel.
On computers with intelligent thermal management, it is normal for the fans to be running at high speed while using Apple Hardware Test.
Advice about hardware compatibility
When running Apple Hardware Test from the Mac OS X installation DVD, the DVD is not ejected on computers with a tray-loading optical drive when you click the Restart/Shut Down button. Either manually eject the DVD or use Mac OS X to eject the DVD.
Advice about resolving problems with your computer
• Turn the computer off and on properly.
You can often eliminate problems by turning off your computer as recommended. To turn off your computer, choose Shut Down from the Apple () menu. Do not turn off the computer by turning off the switch on a power strip or by pulling the computer’s power plug. Restart your computer by pressing the power button. To restart your computer when it is on, choose Restart from the Apple () menu.
• Check cables, peripherals, and controls.
To see if cables or peripherals are causing conflicts with your system, shut down your computer. Disconnect the cables and peripherals, such as printers, scanners, cameras and external mass storage devices. Then reconnect the cables and peripherals and restart your system. You can also adjust the controls on your monitors and other peripherals.
• Start up from the DVD containing the Mac OS X software.
Start your system from the DVD containing the Mac OS X software by holding down the "C" key until you see the Apple logo. If the system works properly when started (booted) from the DVD containing the Mac OS X software, the problem may be related to the software installed on your computer.
• Refer to Mac Help and the Internet for assistance.
Mac Help, located in the Help menu, includes a wealth of technical information. The AppleCare Knowledge Base and other resources for technical help and support are available 24 hours a day at www.apple.com/support.
• Reinstall the Mac OS X.
In many cases, a clean installation of the Mac OS X fixes recurring problems. Make sure you back up the data on your hard drive before reinstalling Mac OS X. Follow the instructions in the Read This First or Read Before You Install documents to reinstall Mac OS X.
• Contact AppleCare Service and Support for assistance.
If the above steps don’t resolve the problem, please review the service and support material that came with your computer for information on contacting AppleCare.
Copyright 2000-2008 Apple Inc. All rights reserved. Apple, the Apple logo, MacBook Air, FireWire, are trademarks of Apple Inc., registered in the U.S. and other countries. AppleCare is a service mark of Apple Inc., registered in the U.S. and other countries.
January 2008