Hi Martin,
I currently run Windows Defender (with real time protection on) along with
ESET's NOD32 for antivirus protection. The combination works extremely well.
If interested you can get additional information directly from their site.
http://www.eset.com/index.php
I had used both Norton and McAfee products in the past and it seems a number
of various problems continually surfaced. NOD32 has eliminated all problems,
the program has a small footprint, is easy to remove if not satisfied,
updates frequently and offers excellent protection. So good I have added the
AV product to all six home PC's.
I do recognize that a number of other AV's products exist and work well but
I think their names are not NORTON or McAfee.