This is probably one of your programs trying to check for updates but it could be something you've downloaded trying to do some spying. I suspect that the only way to stop it is to try it and see what happens. First, make sure that your virus checker is up to date and then do a thorough scan. I then recommend getting rid of all your undesirable cookies (or perhaps all cookies). IN IE, go to <Tools><Internet Options> and, on the <General> tab, delete your Temporary Internet Files.
Now, reboot and allow the PC to go on-line and see what site it tries to access. Unless you are happy with this access, close your connection immediately, but you will now know where to follow your investigations.