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. For help reinstalling, hold down the House icon at the top of this Help window, and choose Mac Help. Type “reinstalling” in the Help Viewer’s search field and press Return.