We have a new computer. Windows 10 OS. 

Minecraft Launcher runs fine on the old computer (also Windows 10).

On this computer we have had multiple bugs. We've had one case of an error message that launcher disappears after running and when tried again we get a message that the game is already open. The most frustrating and frequently repeated bug is that the launcher hangs/stalls on the Mojang loading screen. In fact, there are two screens. The only way out is to log out. We have battled this for 3 days and fixed it once by clicking off the modded box. We have uninstalled/reinstalled, restarted, turned off firewalls, cleared cache, etc. Multiple times. Perhaps a bug with sync as it insist on opening sync eventho Chrome is default. We've run out of ideas. Please help!