Should my PC be sending millions of packets of internet data at startup?

After I boot my PC and log in, the "local area connection status" shows typically 7 million packets of data sent, and 25 packets received. Is this normal or does it suggest a virus/spyware? I have AVG Free installed and a recent scan is clear. I also scan regularly with Malwarebytes, again all clear. I also installed SpyBot, and that gave a clear scan, though I removed it afterwards because its essential service would not start automatically as supposed to.

On one occasion, when my PC had been on for a while, there was a flurry of disk activity after which it said 30 million packets sent. That's a heck of a lot of data, about 2GB if I'm right in thinking the packet size is 68 bytes. Anyone any ideas?