I have backed everything up, (Mavericks installation too!) and want to give Yosemite a go. But when it finished downloading it says it failed to download, I can't remember the exact error code, but it was just about under a minute or so before it completed. I don't know what else to say, i wasn't doing anything, I was just letting it download while i was messing around with my Domain Server for study (my mac is not on the domain). It is however connected to the Ethernet and Wifi. Have installed the latest updates, so everything is good to go there. Any suggestions?