I just replaced the hard drive (to a 1T senate SATA) in my MacBook Pro and upgraded the RAM from 2, 2GB cards to 2, 8GB cards.
Hardware install went smooth, backed up old drive to time machine & made a USB of OSX for install on new drive.
I've gone in and reformatted the new drive with the proper settings (1 partition, journaled, etc...).
When I go in to boot up the system, the computer goes to apple logo grey screen and the loading bar comes up, loads to exactly the halfway point in about 6 minutes, then just sits there... For hours.
I've tried it many times always with the same outcome.
I need my computer for school TODAY!