PORT 80 open

I am runnind Win 7 Ultimate Actiontec GT701D DSL Modem Dlink DIR601 router.
 All is stealth except for Port 80.
 If I reboot the router and modem all ports are stealth.
 Shut down for the day and reboot port 80 0pen again so I reboot router and modem and all are stealth again.
 Is there a fix for this?
 Thanks