[MovedGoalPosts]

Changing mac addresses shouldn't be necessary.

Reset the router so that it works as manufacturer's default and picks up the IP automatically from the Modem. Reset your computer so that uses it's normal mac addy (if you had changed that) and the Ip is set to auto acquire.

Now make sure you power off the modem, router and PC. Power on the modem, let lights settle, then the router, then the PC. Remember every time you change the device directly connected to the modem, the modem must be rebooted.