I can't open any application on my Mac Book pro. The message tells me it may be damaged or incomplete. What can I do?

Gosh-sounds like you have a problem- no kidding, right? Without knowing which application in

Particular is incomplete or damaged, all I can suggest is to boot from the Recovery Partition ( Apple + R keys held down on reboot of Mac, run disk utility, re-install OS. This should not affect any data on your MacBook Pro at all

Good luck

John B

Do you mean to say you cannot open Apple-Installed items from the /Applications folder?

Or perhaps you meant to say you could not open a NEWLY DOWNLOADED Application?