On a Windows 7 SP1 running in a Hyper V machine on 8.1, the Windows 10 upgrade app icon that should be in the System Tray is missing. I have removed a KB3035583 update that caused the app to claim there is not enough RAM (there is 3 GB). A KB3035583 update and a KB2952664 update were installed yesterday (Aug 11, 2015). The Win 10 upgrade app icon is still missing. I suspect this is a Microsoft bug but I am not sure.