Can anyone tell me how often I.P addresses are changed?

I guess I am aksing if the I.P address on a person's computer is changed every so often? I have heard many times that I.P. address are changed for security, to protect people's I.D?
And, I ask selfishlly because, after being on yahoo messenger, chat....the last thing I want is for someone to try and find me using my IP address. I have probably asked too many questions here. Sorry. But, any answers?

Your ip address is (typically) dynamically assigned to you by your Internet Service Provider (ISP) and is only good for a certain amount of time. When your ISP assigns an IP to you, it is called a "lease" and does have an expiration date/time associated with it. The lease time varies by ISP. On the other hand, your ISP may be assigning you a "static" IP address that never changes. You generally have to request (and pay for) a static IP address, however.

Assuming you do not have a static IP address, if you wish to change your IP address, you can "force" your ISP to give you a new IP address. If you turn off your DSL/cable modem (and router if you have one) for approximately one hour then turn back on, your IP address should be different. If you use dial-up for your internet connection, your IP address will likely be different every time you log back in already.

Hope that helps!

On Dial-Up, your I.P changes every time you log on. On broadband, it varies.

I don't think it changes,it is a form of id. and is recorded when when you visit most sites......

they CAN change all the time, but they dont have to. My cable modem IP address hasn't changed in 2 years. If you're worried about privacy, look into an anonymizing proxy like Tor. Generally, there's no way to map an IP address to a specific house - HOWEVER, you can usually map it to an area, and then if you told someone your real name, they can look for anyone with your name in that area.

there are two types of ip address,one is static ip address which is a number that is assigned to a computer by an Internet service provider (ISP) to be its permanent address on the Internet.Computers use IP addresses to locate and talk to each other on the internet.

other one is dynamic ip address,dynamic ip
is automatically assign ip address to the pc.it changes everytime you connect to the internet by the isp.

Your IP is almost guaranteed to be dynamic.. meaning it changes. How often could be everytime you disconnect and reconnect to the net, or it could be leased to you for a few days, as mine does. Your IP won't reveal much more than who your service provider is.. period.
Now it is possible to get hacked if you transfer files among PC's with IM .

No one can find you based on your IP. It's just a number your provider gives you and can't reveal your home address or your name

edit; Do a whois on your IP. Just search for "whois".
You may find it will report your area to be nowhere even close to where you live. I do one on mine and it says I'm over 150 miles from where i really live.