Before we begin, you should make sure that you've got a laptop or desktop with a wireless card that isn't currently connected—if your laptop is connected to the wired network, your wireless card should be free, and we can use it to allow access to the internet. Note that you have to be plugged into a wired connection in order to share the connection wirelessly with others, or have a second wireless card. Readers should also note that this won't work on (some) work networks that use group policies to enforce TPS report cover sheet boredom and prevent you from having any fun at all.
You'll want to start out by heading into the Network and Sharing Center through the Control Panel, or you can quickly get to it by right-clicking on the network icon in the system tray. Once you are there, find the link for "Set up a new connection or network".
You'll be prompted with a wizard that allows you to connect to VPNs, dial-up, or create a new ad hoc wireless network, which is what we want to do. You can easily use an ad hoc network to share files back and forth between two computers, but today we'll be using it for sharing the internet connection.
You'll need to give your network a name and choose some security options—remember that
WEP is extremely easy to crack—and you'll want to make sure to use at least a decent sized key even for WPA2. The really important option on this page is to remember to check the box for "Save this network".
At this point your ad hoc network should be running and ready to start connecting your devices, but you'll want to hold off just a minute.
You'll notice that the ad hoc networks that you create get added to the quick-select wireless network list—when you disconnect from your ad hoc network, it's the same as stopping it. Connecting to the network is the same as starting it back up; this way you can quickly switch back and forth between connections with just a few clicks.
The last step is enabling connection sharing through your regular network card, which will allow anybody connected to your ad hoc wireless to use your internet connection. To do so, you'll want to head into the Network and Sharing Center, click the "Change adapter settings" link on the left, and then find your network connection in the list—it's very important that you only enable internet connection sharing on the adapter that is actually connected to the internet. In this case, my internet access at work goes through my Local Area Connection, so I've enabled it there.
At this point, you should be able to connect any wireless device to your new ad hoc network and access the internet, or even share files directly with your laptop.
