Explorer.exe crashes constantly (due to Norton360 DLL). Norton claims it's a MS/OS issue only. Is it?

On boot into Windows 7 I get a good login but no explorer.exe is started. Hence, no desktop, no GUI generally.

I can start task manager with Ctrl+Alt+Del and run programs from there, including cmd.exe, msconfig, even Firefox.

So I have a semi-working system. Starting explorer.exe manually results in immediate crashes. Eventvwr log below. I've run full system scans with a variety of software including Norton360 boot recovery and Power Eraser, Kasperskey, and now running full system scan with Microsoft MSRT. So far nothing comes up. If it's malware it's very invisible.

Every attempt to start explorer.exe results in the following event situation (Event Viewer log):

Faulting application name: explorer.exe, version: 6.1.7601.17567, time stamp: 0x4d672ee4
Faulting module name: EFACli64.dll, version: 3.0.2.34, time stamp: 0x4ed5ce9f
Exception code: 0xc0000005
Fault offset: 0x000000000000e5b4
Faulting process id: 0x15f0
Faulting application start time: 0x01cd363bbb2612bd
Faulting application path: C:\Windows\explorer.exe
Faulting module path: C:\Program Files (x86)\Norton 360\Engine64\6.2.0.9\EFACli64.dll
Report Id: fa008352-a22e-11e1-a8aa-001d729e5a6c

UPDATE: I just had a remote control session with Norton tech. They said this is OS issue and passed it to MS. I haven't tried a session with MS but that seems next logical step prior to repair with boot disk.

My question now is what is the significance of the "faulting module"? This is the Norton 360 dll by the name of EFACli64.dll. Norton rep seemed to imply it meant nothing in particular. But everytime I try to start explorer.exe manually I get that error log packet exactly, and Norton 360 just updated yesterday.

So I'm wondering. If this is strictly OS corruption. If it's malware it's really stealthy. Nothing has caught a whif of anything: as above, Kasperskey, Norton, MS full scans reveal nothing.

Is this just MS Windows 7 corruption or is newly updated Norton 360 to blame?

Update:

I'd earlier attempted a System Restore which didn't happen because on restart it wouldn't remember the process. I just now did a System Restore from a Windows 7 boot usb disk. The System Restore went through flawlessly, but the OS has the same issue on reboot.

Have you tried uninstalling Norton completely? You can get to Add / Remove programs by running appwiz.cpl from the Task Manager.