Windows 7 Home Premium
Trend Micro Titanium AV
Most noticeable symptom is that the desktop icons & task bar started flashing on and off every 5 seconds or so. You can run other programs when that starts but you cannot run any Windows items like control panel, file explorer etc. You can run Outlook, Chrome and others.
It does not happen in safe mode. It does not happen for about 10 minutes after the computer boots. Did determine that it does happen right after "Windows Explorer has stopped working" message. Also noticed that dllhost.exe *32 process goes really high when this is happening too -- 100,000+.
Ran sfc /scannow. Still happens.