Thanks for the reply. I have weather gadgets running, but they've been there for some time with no issue. The process which is creating the majority of the network traffic is the system process you can see in the screenshot which is transferring with my D-Link NAS. I expect occasional traffic from my gadgets as they need to update, but I'm not sure where the constant traffic to my nas is coming from. Whenever I'm away from my home network I don't have the problem, but as soon as I reconnect to the my home network windows starts transferring to and from my NAS like crazy.
Thanks for your help,