Disable ICS (Internet Connection Sharing) in Windows 7
If you previously enabled Internet Connection Sharing (ICS), and you decide to use a router instead of ICS to share an Internet connection among two or more computers, you'll need to disable ICS.
- Open control Panel, then click on Network & Internet category to open Network Connections.
- Right-click the shared connection, and then click Properties. If you are prompted for an administrator password or confirmation, type the password or provide confirmation.
- Click the Sharing tab, clear the Allow other network users to connect through this computer's Internet connection check box, and then click OK.
Here's some info on ICS:
It works on a per-connection basis, so you'll need to disable it for the adapter that you don't want to share [wireless (wifi), wired (LAN), modem (USB based devices)].
Also, for a blanket "no-sharing" you can turn off the service itself:
Start -> Run -> services.msc (not sure if its there for Home Premium) -> Internet Connection Sharing (ICS)
Double click & choose 'Startup type' as 'disabled'
You may also want to consider disabling it if you dont have multiple computers or if you dont share a single Internet connection, on one computer, between other computers, in the same local area network.
Addl read : Description of Internet Connection Sharing