I have Mac OSX 10.9.5, Mavericks, Mac is mid 2007 , 4 GB memory, have tried to download Yoesmite six times, always fails near end, about 2 hours left, download speed 3.42 MBPS, slow sped on Comcast, took 14 hours for Mavericks, Changes the DNS from 75 to 8, still no go. Any ideas or should I just forget it. ?