After upgrading from windows 7 to 10,  IE 11 doesn’t open.  I have searched a lot but didn’t find a solution.  One solution suggested it was due to logitech camera’s process monitor. but removing that didn’t solve the problem.   The error log in event viewer was this:

Faulting application name: iexplore.exe, version: 11.0.10240.16412, time stamp: 0x55b99d3f
Faulting module name: ntdll.dll, version: 10.0.10240.16430, time stamp: 0x55c59f92
Exception code: 0xc0000409

After some digging, it turned out it was due to EMET 5.2 Microsoft mitigation service.  seems Microsoft security service breaks its own program.   I uninstalled it, IE 11 worked. I reinstalled it after downloading it again from Microsoft site.  IE 11 stopped working.  I opened EMET notification and went into apps and tested the different checkboxes for IE.  unchecked EAF and leaving other checks worked.

TL;DR;  If you have EMET 5.2 installed, opening EMET, going to APPS -> unchecking EAF in front of Internet Explorer and then OK should make IE work again.  what security implication that means not sure. but Microsoft should fix this soon.