IP Address

All of a sudden today when I try to connect to my internet on my Macbook it says someone else is using my IP address. I have rebooted our modem system and everything - every other non Apple computer in the house works on INternet.

How do I stop having my IP address being used by someone else or do I need change my IP address - and - how do I do that?

Do you have static IP addresses assigned to all devices or do you use IP addresses assigned by a DHCP service ?
If static, you need to have an IP plan ( which device has which IP address )
If DHCP assigned, renew your IP address ( From System Preferences )

Hope this helps

Cheers ... McBie