If you only have a single plain wired internet connection to one pc and you want to use that connection with multiple devices, such as you mobile phone or laptop, there are a few options available.

One of the easier ways is to use connectify.me, a software that will make it happen fast, easy and free on your Windows 7 machine.

A friend of mine needed this and was able to set it up all by himself in just a few minutes and got his HTC desire (Android phone) connected to the internet without having to use mobile data connection. (the only internet connection available was a network cable)