Now you will need to configure the host computer, i.e. the computer that has the broadband Internet connection. As explained in the introduction, Windows XP supports only WEP encryption, which is very weak, so the host computer needs to be running Windows Vista or greater in order for you to enable WPA2, which is a secure encryption method. You can, at your own risk, build your ad-hoc network using a host computer running Windows XP, but don't get back to us complaining that your network got hacked. This requirement is only for the host computer. Client computers can run Windows XP without any security risk.

If you are sharing your Internet connection using a regular broadband router (i.e. without wireless capability) any computer connected to the router can be configured as host, as long as it is running Windows Vista or greater. As we already mentioned, you cannot turn off this computer or all other computer will lose access to the Internet.

The step-by step to configure the host computer using Windows Vista is as follows.

1. Go to Start menu, Control Panel, Networking and Sharing Center. On the window that will show up, click on the item "Manage Wireless Networks" present on the menu on the left-hand side.

2. The window shown on Figure 4 will appear. You need to click on "Add".

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Figure 4: Managing wireless networks.

3. The menu shown on Figure 5 will appear. Choose "Create an ad hoc network".

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Figure 5: Choose "Create an ad hoc network".

4. On the next window simply click on "Next".

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Figure 6: Click on "Next".

5. Now Windows Vista will ask you the properties of the network you are creating (see Figure 7). You will need to fill out the following:

• Network name: This will be the name of your network. This is how your computers will call your network. In our case, we called our network “Gabriel”. We suggest you to use a specific name instead of a generic one (e.g. your name or your business name), so you will be able to easily recognize your own network from the list of available wireless networks.
• Security type: Select "WPA2-Personal".
• Security key/Passphrase: Users willing to connect to your network wirelessly will need to configure this key (think of it as a password to access your network) on their computers. You need to create a random key containing 63 alphanumeric characters. It can be shorter, but we don’t recommend. Just go crazy pressing random characters on your keyboard, don’t feel tempted in actually typing something that make sense (see example on Figure 7; obviously don’t use the example we are giving). After typing this random 63-character word, click on the box "Display characters" and select your key, copy it to Notepad and then print it.
• Check the "Save this network" box.
• Click on "Next" after you are done.

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Figure 7: Creating our own wireless network.

6. On the next window you have to click on "Turn on Internet connection sharing", so other people will be able to access the Internet wirelessly.

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Figure 8: Click on "Turn on Internet connection sharing".