[Pockettes]

My firewall says my cable company is trying to send a packet to my computer.

Why would they do that?

[lunarlander]

Some ISP try to detect if their users are running web servers, because the usage policy says they are not allowed to run a web site.

[Pockettes]

I did install have some server thing trying to run on my PC after install visual studio 2005 to learn it. Maybe that had something to do with it. I have uninstalled it as it was doing weird stuff. thanks

[Elvandil]

Or to see if you are still online, or to test the connection. There are literally 100's of packets coming in at all times from many places, from people scanning for open ports, to web-crawling search engines, to researchers taking measurements. You'll go crazy trying to track them all down.