By the nature of your question alone, have you experienced the same problem when your laptop has not been connected to the internet? You specify hardware for your router and your ISP however what makes you think that this is an internet related problem?
Some product info about your Laptop may be beneficial..
Also, is there any trend to what your are doing when your laptop freezes OR are there any error messages, strange sounds etc beforehand?
To me, it may be a driver or dll causing an error (e.g. the classic 'AVI file problem' causing explorer to crash out).. If not, then it may be hardware related.. if your laptop is one of the standard 'off the shelf' one's.. invest in some decent RAM from Crucial or something.. helped mine loads!!