AVG can break IE 11 if Trusteer is installed

If you’ve been having problems with Internet Explorer 11 failing to start in the last week then you may have fallen foul of a strange convergence of AVG, Internet Explorer and the Trusteer add-in for the same.

The symptom is that following an update (probably to AVG but not certain) the machine refuses to load Internet Explorer. If you look in the Event Viewer you can see the application starting and then crashing immediately. The error code is 0xc000005 and the location is helpfully ‘Unknown’.

If you reset IE to defaults (including user defaults) then the problem remains.

If you remove IE 11 from the machine and fall back clumsily to IE 9, then the problem goes away but you’re stuck with IE 9. Reinstalling IE 11 brings the problem back.

This doesn’t appear to affect all workstations (as others have AVG Cloudcare installed) but it does affect those that also have the Trusteer add-in installed.

Strangely and perhaps counter-intuitively, the fix is to add c:\program files\internet explorer\iexplore.exe to AVG’s exception list (or perhaps remove Trusteer which you wouldn’t really want to do).

This will get you going, but I’d diarise a reminder to wait a few days, update AVG and see if removing the exception breaks it again. I’m not a fan of exceptions to executables being left lying around.