I am running Windows 7 Home Premium 64bit Service Pack 1, Norton Internet Security 22.5.4.24(NIS), Mozilla Firefox 40.0.3(MF40) and Internet Explorer 11.00.9600.17840(IE11).
Until recently, I was running Internet Explorer 9(IE9). I couldn't open MF40 or IE9(They would briefly appear in Task Manager, but windows wouldn't open for either). They would both open/run when I booted in Windows Safe mode.
I ran NRnR and also upgraded to IE11. MF40 now opens/runs, but IE11 exhibits different symptoms than IE9, i.e., a window opens displaying 'Internet Explorer (Not Responding)' for a few seconds and then closes. IE11 opens/runs when I boot in Windows Safe mode.
Any suggestions will be appreciated.