I wasn’t sure the best place to put this, sorry if its the wrong area. Also I do realize Windows 10 preview builds are not meant to be totally reliable but this seems to be an Avast issue and I wanted to make this issue known in case anyone else is running similar software.
It seems the new Avast 17 causes a boot issue on newer builds of Windows 10 including 15031. Avast 12 (I believe it is) seems to work just fine. I’ve tested this across multiple installs, multiple windows 10 builds in the 150xx tree and tested installing nothing but Windows and Avast.
I’m guessing its an issue with the newer kernel driver, however it breaks Windows so badly that you have to reset the PC to fix it.
If you’re running Windows 10 150xx and use Avast, do not let it upgrade to version 17! If it does, do NOT reboot until you have uninstalled Avast via add remove programs or you will boot loop and neither safe mode, command prompt nor system restore seem to work. Once version 17 has been removed you can reboot safely and reinstall an older version.