The Avast Emergency Updater is causing this problem. Unfortunately, that feature is completely broken in Avast 2014. I am having the same freezing problems. The solution is to turn off avast self-protection module in avast troubleshooting settings, enter task manager, and end the 154235523-5353somemorenumbers.exe process, which is the avast emergency update file as it is digitally signed by Avast. After killing the process, the freezing is gone. Happens several times a week for me, and I never had this problem with previous versions before updating to 2014, which I now realize was a mistake.