How to use the Alternate Configuration functionality to establish multiple-network connectivity

If you want to use your laptop on both office and home networks without having to manually reconfigure TCP/IP settings and one of those networks does not have a DHCP server, you may be able to do this by using the XP Alternate Configuration functionality. For example, when you are in the office, the computer uses a DHCP to assign TCP/IP configuration. When you are at home (where you do not have access to a DHCP server), the computer automatically uses the alternative configuration. To do this, go to Control Panel>Network and Internet Connections>Network Connections, right-click the connection that you want to configure and clickProperties. Click Internet Protocol (TCP/IP)>Properties>Alternate Configuration, and assign IP, default gateway and DNS manually.

Set up a wireless network without a router

Wireless networks are helpful because they let you use your computer and connect to the Internet anywhere in your home or office. However, most wireless networks use a wireless router, which can be expensive. If you have more than one computer, you can set up a wireless network without buying a wireless router and save yourself some money.

In a traditional wireless network, a wireless router acts as a base station, much like the base station for cordless phones. All wireless communications go through the wireless router, allowing nearby computers to connect to the Internet or to each other.

Ad hoc wireless networks work more like walkie-talkies, because the computers communicate directly with each other. By enabling Internet Connection Sharing on one of the computers, you can share Internet access.

Ad hoc networking might seem like a much smarter alternative to using a wireless router, but it does have a couple of disadvantages:

•	If the computer connected to the Internet is shut down, all computers that are part of the ad hoc network lose their Internet access.
•	To connect to the Internet, one computer always needs a wired network connection.

To connect your computers to the Internet using an ad hoc wireless network, follow these high-level steps (described in more detail later in this article):

1.	Enable Internet Connection Sharing on the Internet-connected computer. You can skip this step if you don't need to access the Web.
2.	Set up the ad hoc wireless network on the Internet-connected computer.
3.	Add your other computers to the wireless network.

How to enable Internet Connection Sharing

On networks with wireless routers, the router has the important job of forwarding communications from the computers on your home network to the Internet. On ad hoc networks, you must designate one computer to serve this role. The computer you choose must have a wired connection to the Internet, and it should be left on whenever you want to be able to use your other computers.

How to set up the first computer

To set up an ad hoc wireless network that allows computers to share an Internet connection without a router

1.	If necessary, install a wireless network adapter.
2.	Click Start, and then click Control Panel.
3.	Under Pick a category, click Network and Internet Connections.
4.	Under or pick a Control Panel icon, click Network Connections.
5.	Right-click your wireless network connection, and then click Properties.
6.	In the Wireless Network Connection Properties dialog box, click the Wireless Networks tab.
7.	On the Wireless Networks tab, under Preferred networks, click Add.
8.	In the Wireless network properties dialog box, on the Association tab, type the name of your ad hoc wireless network in Network name (SSID) box (shown in step 10). For example, you could name your wireless network MyHomeNetwork.
9.	Clear the The key is provided for me automatically check box and select the This is a computer-to-computer (ad hoc) network check box.
10.	Create a 13-digit password and type it in both the Network key and Confirm network key boxes. For the best security, include letters, numbers, and punctuation. Then click OK.
11.	Click OK again to save your changes.

How to set up additional computers

If the computer you want to add to your network does not have built-in wireless network support, install a wireless network adapter.

Windows XP automatically detects the new adapter and notifies you that it found a wireless network.

Now connect your computer to your wireless network

Note: These steps apply only if you're using Windows XP Service Pack 2 (SP2). If you haven't installed SP2, visit Microsoft Update to install it before connecting to the ad hoc network.

1.	Right-click the Wireless Network icon in the lower right corner of your screen, and then click View Available Wireless Networks. Note: If you run into any problems, consult the documentation that came with your network adapter. Don't be afraid to call the manufacturer's technical support department for help.
2.	The Wireless Network Connection window appears and displays your wireless network listed with the SSID you chose. If you don't see your network, click Refresh Network List in the upper left corner. Click your network, and then click Connect in the lower right corner.
3.	Windows XP prompts you to enter a key. Type your encryption key in both the Network key and Confirm network key boxes, and then click Connect.

Windows XP shows its progress as it connects to your network. After you're connected, you can close the Wireless Network Connection window.

Repeat these three steps on each computer that you want to connect to your ad hoc wireless network.

Now you're ready to browse the Web wirelessly, from any computer you add to your home network.

Set up a wireless network

Choose your wireless equipment

The first step to setting up a wireless network is to make sure you have the equipment you need. You'll need at least two network components: a wireless router and a wireless network adapter.

If you're buying a new router, look for one with the Windows logo. This ensures that the router will work reliably in Windows XP, and if you decide to upgrade, it will work in Windows Vista and Windows 7 as well. Networking in Windows 7 has been simplified and improved. To learn more, see Windows 7 features.

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Wireless router. Converts the signals coming across your Internet connection into a wireless broadcast, sort of like a cordless phone base station. Be sure you get a wireless router and not a wireless access point. For more information about choosing a wireless router, read Choosing the type of network to install.

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Wireless network adapter. Connects your computer to your wireless router. If you have a newer portable computer, you might already have wireless capabilities built in. To find out if you have wireless networking built in, and for more information about buying and installing a network adapter, read Install a wireless network adapter. Make sure you have an adapter for every computer on your network.

You can also connect your digital video recorder (DVR) or media extender to your wireless network. If the device has a wired network connection, use a wireless game adapter for a single device or a wireless bridge to connect multiple devices. Wireless game adapters aren't just for games—they'll work with anything that has a wired network port. For information about connecting game consoles to your network, read Connect an Xbox or Xbox 360 to your network.

Connect your wireless router

1.	Before you go any further, print these instructions. You'll be temporarily disconnected from the Internet, so while you're doing the installation, you won't be able to get to this page to refer to the instructions.
2.	Locate your cable modem or DSL modem, and unplug it from its port to turn it off. • If you connect your modem to the wall in a similar way that you connect your TV to your cable television outlet, you probably have a cable modem, and it probably has a coaxial cable connected to it (like the round black or white cable you plug into your TV). • If you connect your modem through the phone lines, you probably have a DSL modem, and it probably has a phone cable connected to it.
3.	If you currently use a dial-up connection to connect to the Internet, set up your wireless network using ad hoc Internet sharing.
4.	Connect your wireless router to your modem. Your modem should stay connected directly to the Internet. Later, after you've hooked everything up, your computer will wirelessly connect to your router, and the router will send communications through your modem to the Internet. To connect your router to your modem: • If you currently have a computer connected directly to your modem: Unplug the network cable from the back of your computer, and plug it into the port labeled Internet,WAN, or WLAN on the back of your router. • If you don't currently have a computer connected to the Internet: Plug one end of a network cable (included with your router) into your modem, and the other end of the network cable into the Internet, WAN, or WLAN port on your wireless router.
5.	Plug in your router. After a minute or two, the Internet, WAN, or WLAN light on your router should light up, indicating that it has successfully connected to your modem.

Configure your wireless router

There are two ways to configure your wireless router: using Windows Connect Now and manually.

•	If your router supports Windows Connect Now, you don't need to continue reading this article. You can configure your wireless router and Windows XP computers quickly and easily by following the instructions in Using Windows Connect Now technology.
•	If you don't have a router that supports Windows Connect Now, you need to manually configure your router:

1.	Using the network cable that came with your wireless router, temporarily connect your computer to one of the wired network ports on your wireless router (any port that isnt labeled Internet, WAN, or WLAN).
2.	Turn your computer on; it will automatically connect to your router.
3.	Open Microsoft Internet Explorer and type in the address to configure your router, as described in your router's instruction manual.
4.	Create a password if a prompt appears. The address and password you use will vary depending on what type of router you have, so refer to the instructions included with your router. Tip: As a quick reference, this table shows the default addresses, user names, and passwords for some common router manufacturers. Router Address Username Password 3Com http://192.168.1.1 admin Admin D-Link http://192.168.0.1 admin (leave blank) Linksys http://192.168.1.1 admin Admin Netgear http://192.168.0.1 admin password
5.	Internet Explorer will show your router's configuration page. Most of the default settings should be fine, but you should configure three items: • Set your wireless network name (known as the SSID) to something unique that does not identify your name or address. • Enable Wi-Fi Protected Access 2 (WPA2) encryption to help prevent uninvited guests from connecting to your wireless network. Note: We don't recommend using WEP. WPA-2 is more secure. If you try WPA-2 and it doesn’t work, we recommend that you upgrade your network adapter to one that works with WPA-2. • Set your administrative password to prevent others from configuring your router.

The exact steps you follow will vary depending on the type of router you have. After each configuration setting (SSID, WEP, and administrative password), be sure you click Save Settings, Apply, or OK to save your changes.

Note: The pictures in this section show Linksys wireless equipment. Equipment from other manufacturers will vary in appearance. For example, to save your settings in Linksys, you click Save Settings. Other equipment may have a different display, and you may have to click Apply or OK.

SSID or naming your network

A service set identifier, or SSID, identifies your network. Choose a unique name that you're confident none of your neighbors will use, but don't specify your name or your address. This is not a security tool, so you don't need to make the SSID complex.

Protecting your wireless network

Help prevent uninvited guests from connecting to your wireless network. To learn how, read Implement WPA2-Personal wireless security on a Windows XP SP2-based computer.

Administrative password

The last configuration change you should make is to the administrative password. Just like any other password, the administrative password should not be a word you can find in the dictionary, and it should be a combination of letters, numbers, and symbols. Be sure you can remember this password, because you'll need it if you ever have to change your router's settings.

Tip: Write down your passwords on a piece of paper and store them in your home safe if you have one. If you don't have a home safe, store your passwords with your other important family documents. If you think of your passwords as important documents, you'll always know where to find them.

Now that you have configured your wireless router, named your wireless network, protected it, and assigned an administrative password, you are ready for the last step:

•	Disconnect the network cable from your computer—you'll be able to connect wirelessly from now on.

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Connect your computers and devices

If your computer does not have wireless network support built in, you can install a wired or a wireless network adapter. Windows XP will automatically detect the new adapter and might prompt you to insert the CD that came with it. The on-screen instructions will guide you through the configuration process.

Windows XP Service Pack 2 (SP2) is not required for wireless networking, but it does make setting one up much easier. SP2 also helps protect you against viruses, worms, and other Internet intruders. To install SP2, visit Microsoft Update. The steps below apply only if you're using SP2. Windows XP will show an icon with a notification that says it has found wireless networks.

To connect your computer to your wireless network

1.	Right-click the wireless network icon in the lower right corner of your screen, and then click View Available Wireless Networks. Note: If you run into problems, consult the documentation that came with your network adapter. Don't hesitate to call the manufacturer's technical support number for help.
2.	The Wireless Network Connection window appears and displays your wireless network listed with the SSID you chose. If you don't see your network, click Refresh network list in the upper left corner. Click your network, and then click Connect in the lower right corner.
3.	Windows XP prompts you to enter a key. Type the encryption key that you wrote down earlier in both the Network key and Confirm network key boxes, and then clickConnect.
4.	Windows XP will show its progress as it connects to your network. If the Wireless Network Connection window continues to show Acquiring Network Address, you may have mistyped the encryption key—click Cancel and return to step 3.

After you're connected, you can close the Wireless Network Connection window. Now you're ready to browse the Web wirelessly. You can also create a wireless network in your home that connects your computers, printers, cameras, games, and other accessories for easy access and enjoyment.

IP Address 169.254.0.0

You have probably picked up that IP address because a computer on your network cannot access the DHCP server and Windows has allocated this number.

The Internet Assigned Numbers Authority (IANA) has reserved 169.254.0.0-169.254.255.255 for Automatic Private IP Addressing. As a result, APIPA provides an address that is guaranteed not to conflict with routable addresses.