fej2008

What is the make/model of your modem and router? (if there's any..)

try doing this in command prompt

ipconfig /release (you're ip will change to 0.0.0.0)
then do
ipconfig /renew (it will give you either 192.168.x.x / 169.254.x.x / error message..)

if still 169.x.x.x ip address, try hard reset modem. Poke the hard reset hole at the back of modem (depends on the modem), hold it for 20-30secs.

and also bypass the router if there's any just to make sure.