might want to try this as well:
Power off your computer and any other computers connected to the network. Unplug your router power.
Unplug your cable modem.
Wait 30 seconds.
Plug your cable modem back in
Wait 30 seconds
Plug your router back in.
Wait 30 seconds
Power on your computers
In your computer go to start: run
type cmd
in the command window type these three commands in succession and press enter, waiting about 15 seconds between each
ipconfig /release
ipconfig /flushdns
ipconfig /renew
Then make sure your network card drivers are up to date, your router firmware is up to date, and all windows security updates and firewall updates are up to date.
If you are still having problems at that point it is your cable line or modem, and you need to have the company come and fix it.