I am running windows 8.1. I installed norton security with backup over a copy of norton 360. It has twice stopped working, And it does not seem to scan inbound email for possible malicious attachments. Spent 2 hours on chat with regular techs and after 3 npe scans (two beta) the third finally detected 3 programs and removed them. however NPE did not appear to scan email, or failed to detect any malicious software