My 2011 Mac Mini upgraded to 8GB with Mountain Lion has just frozen. This happend whilst streaming video online. I got the beachball so i had to switch the mac off and on. Now, everytime i switch it on, it takes ages getting to the grey screen with the spinning wheel. When it eventually gets to the login screen i get the beachball again when i've put in my password. It takes about 30mins just to get to the desktop screen. The mouse cursor seems move around as it should but just get beachball when on desktop. I put my old ram back in the mac and its still doing that. Not sure if this is hardware or software issue. Is there are way to boot up in safe mode or to do checks. Ive noticed the hard drive isnt making much noise so not sure if thats related.