If you can’t open Safari or a new Safari window, these suggestions may help.
Make sure your software is up-to-date
Download and install the latest Mac OS X update for your computer. to find out if updates are available for your computer, choose Apple menu > Software Update.
Check your internal disk
Use Disk Utility to verify and, if necessary, repair your disk.
Reinstall Mac OS X
If the other suggestions don’t help, try reinstalling Mac OS X.