Applications won't launch. (Quit unexpectedly)

Question

This problem just started today. I think it may have something to do with cleaning out my hard drive of stuff I didn't need. I ran 2 programs, Monolingual, which deletes all unnecessary languages from Safari, Adium, etc. The other program I ran was iDefrag, which obviously defragments your hard drive.
Now, a bunch of my applications won't open, but rather I get the '___ quit unexpectedly' dialog. For some reason, iTunes seems unaffected, but Safari and Firefox and Disk Utility and a whole slew of other apps (pretty much every Apple app that I tried to open) won't even open, and I get the 'quit unexpectedly' message.
Does anyone have ANY clue why this is happening? I've tried restarting, but nothing. And I can't even repair my disk permissions because Disk Utility and Terminal won't open, they are messed up as well.
Message was edited by: bangarang!

Answer 1

HI and Welcome to Apple Discussions...
Try deleting this file.
com.apple.LaunchServices.plist
/Users/YourName/Library/Preferences. Drag that file from the Preferences folder to the Trash, empty the Trash and restart your Mac.
Also, make sure you have sufficient disk space.
Right or control click the MacintoshHD icon. Click Get Info. In the Get Info window you will see Capacity and Available. Make sure you always have a minimum of 10% to 15% free disk space at all times.
Carolyn