Running 43.0.4 build 20160105164030 (x86 en-US) on Win 7 SP 1 64-bit; attempted upgrade to 44.0.2 as normal on release channel. Get normal download, then "Restart Firefox" button; pressing it shuts down FF but does not restart. Waited a few minutes, then started FF manually (via Taskbar). Still no FF window opens, so I started Task Mgr and found 2 firefox.exe *32 processes running. Killed them, then restarted FF, it shows its still at 43.0.4. Troubleshooting Update History shows no update made. I can repeat the process but considering all the flaky reports I have found in the Mozilla forum regarding upgrading 43 to 44 I am going to backup my profile folder first. Never had a problem w. an upgrade before. Also, should I look for a Mozilla Update/Install "stub".exe anywhere to debug that?