My Mac has been having a lot of problems recently. Often times, I will open up an application like Finder or Chrome that cause my computer to freeze so badly that I need to force a restart. This last time, getting my computer back on has been a challenge. I turn on the computer and get prompted for a password, which I enter correctly. Then I see the Apple logo for a long time and it usually takes me to the same page where I enter the password. But the page doesn't respond to my keyboard or trackpad... everything is frozen. I tried using the install disc to open up the disk utility and repair my hard drive. But I can't do anything, as it says "Incompatible Format." Has anyone had similar problems? I'm kind of lost at this point. I'm using a mid-2011 15" MacBook Pro.