Not much detail here, however, I will give it a shot.
Turn everything off, cable modem, router, PC(s).
Unplug the USB to the cable modem.
Connect the router WAN port to the cable modem with an Ethernet cable.
Connect the PC to a LAN port on the router.
Power up the cable modem, wait about 30 seconds, power up the router, wait about 2 minutes, power up the PC and see if you can get an IP address and have Internet connection.
JamesO
Turn everything off, cable modem, router, PC(s).
Unplug the USB to the cable modem.
Connect the router WAN port to the cable modem with an Ethernet cable.
Connect the PC to a LAN port on the router.
Power up the cable modem, wait about 30 seconds, power up the router, wait about 2 minutes, power up the PC and see if you can get an IP address and have Internet connection.
JamesO