I have a windows 7 laptop and have windows security essentials installed as an AV.
It has started (actually some time ago) to start up with security essentials in a stopped state, meaning I have to start it manually in the interface.
Fearing a virus have performed a full virus scan (both security essentials and a scan from a boot disk with an up-to-date copy of clamAV) which found nothing. Fearing a corrupt install I tried reinstalling security essentials and this has made no difference.
There is no other odd behaviour and no suspicious processes or network traffic, so I think I am clean.
There is an option to turn on real time protection which is ticked, but no other option (that I can see) that would suggest it should be off on startup. So anyone know what else I can try? it starting to get annoying.