Depends on your system (e.g, you are using wampp,xampp or using dedicated server) open the php.ini file.
Inside the file, you will see the following lines
; Safe Mode
safe_mode = On
make the last line as safe_mode = off
Alright, now the safe mod is off.
Read more about safe mod : http://php.net/manual/en/features.safe-mode.php
Read more about how to work with safe mod in dedicated server:- http://help.godaddy.com/article/119