Hi tigalawilala, welcome to BC.
What type of connection are you using?
If you're on dial-up, your ip addy is dynamic and will change from time to time on it's own.
If you're on cable, your ip is static (never changes). The only way that will work for sure is to call your IP provider and request they change it.
A workaround would be to hide it instead using either an anonymous proxy server or vpn client.
There are free and pay versions of both.
If you want to surf anonymously without installing any software, try Proxify.
It also blocks adds.
A freeware vpn client, such as iPIG
is another alternative. I use it in wireless hotspots.
The more you tell us about your setup, the better we can help you.