Helping people with computers... one answer at a time.
Determining your IP address is easy, but we first have to ask: which IP address do you want? I'll look at determining both.
I need to know my IP address - how do I find it out? I'm running Windows Vista.
For something this simple I still get to pull out my most common answer: it depends.
The good news is that it's actually pretty similar for all versions of Windows.
The question I have to ask, though, is this:
Which IP address do you want?
The easiest way to determine your IP address is to visit one of many sites that will tell you. Just search for "what's my IP" and you'll get a list.
You can also visit this page on Ask Leo! http://ask-leo.com/whats_my_ip_address.html which show you your IP address and a few other things.
Even better, since any web site you visit gets the information I have it right here:
Your IP address is: 126.96.36.199
Open Control Panel's Network and Sharing Center:
You'll see listed a "Network" which represents the network on which your machine is connected. To the far right of it's "Connection" line is a link labelled View Status, click on that:
Click on the Details button:
And there you'll see the elusive IP address that this connection is on.
If you're connected directly to the internet, then the two IP addresses you'll have seen - via an external web site and your machine's network connection information will be the same.
On the other hand, if you're behind a router it's likely that the two will be different. Your computer's IP address will be one assigned by the router - most often a 192.168.x.x address. The router handles translating that (using NAT or Network Address Translation) to the external IP address when you access the internet. In fact, you may have several computers connected to your router, each with their own local IP address assigned by that router, but each showing the same external IP address when accessing the internet.
That's why we often refer to a router as an internet connection sharing device. The internet IP address is assigned to the router itself, and it handles sharing that IP address across however many computers you might have attached to it.