CI update from 1.7 to 2.0 getting Fatal error: Class 'CI_Controller' not found in CodeIgniter.php on line 210

[eluser]InsiteFX[/eluser]
Just delete the CI system directory and copy the new one over, then in your files
change Controller to CI_Controller, Model to CI_Moidel and make sure you copy
the new index.php file over. Replace all the application/config files.

Also It uses the new php Constructor.