First of all go to [Start Menu]>[Run] and type 'cmd'.
In CMD; type ipconfig /all
If DHCP Enabled : No, then it means you do not have a Dynamic IP Address.
A window with a black background and grey text should appear. In this window type 'ipconfig' and text should come up saying:
IP Address ............. *IP HERE*
Subnet Mask ................ *SUBNET MASK HERE*
Default Gateway .......... *DEFAULT GATEWAY*
Write this down on a bit of paper on in notepad. You will need them later.
Now type 'ipconfig/release' - this will terminate your Internet Connection - but don't get scared, you will turn it back on later.
Now go to - Start >> Connect to >> Show all connections - right click your internet connection and click Properties. Now click on 'Internet Protocol (TCP/IP)' and click Properties. If you don't see this, go to Start>>Control Panel>>Network Connections
Once you've click properties, tick/mark the circle that says 'Use the following IP Address' and type in the numbers you wrote down earlier on. Then click ok.
You will be back on the previous window. Click on 'Internet Protocol (TCP/IP)' and click Properties. This time tick/mark the circle that says 'Obtain an IP address automatically'. Click Ok. Click Close.
Now go back onto Command Prompt and type 'ipconfig/renew' this will restart your internet connection and hopefully your IP has changed. If not then repeat the whole process