I have a Local area connection 7 and Local area connection 2
How to delete the other connections so that I can get Local area connections 1 and 2

Have a look here at Microsoft TechNet (http://technet.microsoft.com/en-us/library/cc758990.aspx)

At the page bottom you'll see links to various concepts :

Using local area connections
View the status of a local area connection (Add/Delete connections)
Set up Network Components (Configure)
Network connection icons

You can right-click on the connections and rename them. Give them a more meaninful name like Local Connection, Wireless Connection, VPN Adapter, Bluetooth Adapter, etc.

Assuming 7 is the highest number
_

Renaming the connections will not prevent the next addition from being named 8. You'll need some registry tinkering to avoid that.