24-inch, Early 2009 Processor 3.06 GHz Intel Core 2 Duo Memory 4 GB 1067 MHz DDR3 Graphics NVIDIA GeForce GT 130 512 MB Software OS X 10.9.5 (13F34) OSX 10.9.5 Bought this thing used on ebay and love the new world of iMac, but I have been having problems with it freezing daily. Upgraded it to maverick right away and figured I would be good to go. Not the case. It will just start to kind of pixelate the screen and eventually totally lock up to the point you can't click on anything of find the mouse cursor. Some times it will shut itself off. Others, I have to manually turn the machine off and back on. What gives??