Q: Keep getting error "Could not load Print & Scan preference pane."

Delete what files in your library?

The first thing to do is see if the problem is isolated to your user account. To test that you need to run two tests.

1. Go to

 > System Preferences > Users & Groups

and add a new account. When you're done setting it up, log out of your current account and log into the new one and test for the problem.

Do you see the problem in the new account?

2. Now start up in safe mode by pressing the power button and hitting 'restart'.

After the screen goes blank, hold down the shift key until you see the Apple logo and a progress bar underneath it. You can let the shift key go now.

When the progress bar completes and you see the log in window, log in to your usual account (the one with the problem) and test.

Do you see the problem in your usual account in safe mode?

Report back here with the result of these two tests.

Do you mean you had no luck booting into safe mode?

The trick is to make sure you hit the shift key (just one) early enough. If you're having trouble, power down the computer totally till its off for sure.

Then hit the power button and immediately hold down the shift key and keep it held down until you see the Apple Logo and progress bar. When you get the login screen you'll see 'safe mode' in red in the top right corner of the screen.

You had to 'terminal into safe mode'?? - I'm hoping you mean you set the boot-args to safe mode in Terminal, right?

If you had the same issue in safe mode, in a new user account and your own user account the next step is to reinstall Lion from the Recovery disk.

Backup your data first. This is just a precaution. Reinstalling Lion should not affect anything in your user accounts, but better safe than sorry.

Undo that terminal command so the mac boots normally. Then restart holding down the 'option' key. Choose the Recovery HD. Choose 'Reinstall OS X Lion'.

Relax and have a bite to eat till its done.

EDIT: Whoa - hold that thought - you were doing all these tests with ALL peripherals (like your printer and scanner ) disconnected right? If not, disconnect all peripherals and try again first!

Message was edited by: softwater

Reinstall is overkill.  (This isn't MS Windows, right?)

From:

https://discussions.apple.com/message/15721474#15721474

1. Open: Mac HD/System/Library/Core Services/Directory Utility
2. Click the lock to authenticate changes
3. Click on Directory Editor
4. Click to highlight any extra Guest accounts ("Guest1" "Guest2" etc.)
5. Delete them with the button, leaving only the standard "Guest" account.
6. Reboot

If symptom persists or Disk Utility is crashing, consider this fix:

Copy "PlatformHardwareManagement.framework" from another (working) machine and place it in the same directory on your own upgraded machine.  (File also available on Snow Leopard OS 10.6 Macs.

OR

Use the program "Pacifist" to open the Mac OS X Snow Leopard Install DVD (10.6)

Manually pull out the PlatformHardwareManagement.framework and replace the copy on the hard disk.

I saw other replies where clean install didn't help but the Directory Utility did.

But no joy for you there either?  Removing Guest1,2,3,etc accounts helped most folk.

How about the "PlatformHardwareManagement.framework" swap?  Only saw that one other place and you don't seem to have much to lose.