Hey guys So I finally upgraded from Lion to Mavericks today. I had an appointment with the genius bar today, where I had issues with safari showing websites upside down. They did a hardware test in store and all was fine. Genius suggested its software related. He offered to install Lion again, or Snow Lion, or Mavericks. I go, just go ahead and install Mavericks. He installed Mavericks over Lion, all my files etc were all there which is great. I took my MBA home, and I had a few updates available as you can see on attached image. The first update was for thunderbolt and for mail something to do with gmail. Anyways I went ahead an updated it. I restarted my MBA, when I restarted my MBA I got to the screen that said something along the lines of setting up your mac. So I waited and waited about 35 mins, nothing happened. I called care, who suggested I try and hold down cmd, alt and esc, nothing happened. So they suggested I restart my MBA. Which when I pressed the on and off button, it showed me my log in screen. I go okay. I log in, etc, and then it showed me my desktop. And the update that I tried to update was still showing as if its available to download. I tried downloading it again and restarted my mba. Now when I restarted my MBA the grey logo showed and below that I saw a little horizontal progress bar, which after a few seconds vanished and then my MBA screen goes all black. care then tells me to try it again, and again same issue. However when I look at my updates section, the updated I tried to download, downloaded successfully and was installed. Then it showed me another update available which is the one showing at the top of the image. I have tried downloading this again 3 times, but after the logo comes and goes after a few seconds and that progress bar vanishes, it keeps going back on to the main black screen (as if my MBA is off) I have tried a normal restart and my MBA restarts normally. However this update it does not seem to want to re-start on it, as it takes me to the black screen. I have tried setting up a test account username with full admin, and same problem is showing then too. I have also clicked on to the recovery option, as per care instructions and did repair disc permissions and repair disc and tried it again and still having this problem. So to summarise. I simply cannot seem to install the update that is showing, because when the MBA tries to restart now, it just ends up giving me a black screen. care are going to call me tomorrow now to see how I got on. Any other solutions or suggestions? oh and also whenever i log back in, I keep getting things from keychain asking me for my keychain password. thanks for reading.