If it helps, I think I finally solved the problem I was having. It would appear during the time of the last issues Steam was running in the background and installing a couple of large games. I have bought a few more today in the sales and am getting the exact same issue after about 10 gig of files have downloaded, with more to be downloaded. All my other devices in the house are working fine so it appears Virgin Media are doing something due to the heavy file downloading from my pc.
Thanks for the help and suggestions and I hope this info can help someone in the future.