Before you install Windows XP, ensure that your computer does not have any network cables, wireless adapters or phone cables connected. This prevents network worms from attacking it while it's vulnerable. I also suggest disabling or restricting AutoPlay right away to prevent AutoRun attacks.

Windows XP should have Service Pack 2 installed before you make any network or Internet connections. how does Service Pack 2 help?

My Windows XP disc already has Service Pack 2! Good. Go to Step 3 (below).

My Windows XP disc does NOT have Service Pack 2, or I'm not sure it does Follow all the steps below.

Can I go online using Windows XP without Service Pack 2 or a firewall, and just be careful? NO. Simply connecting a Windows XP computer without firewall protection immediately exposes it to attack. And if it doesn't have Service Pack 2 installed, there's plenty to attack, too.

Question: what about Service Pack 3 for Windows XP? If your Windows XP disc already contains Service Pack 3, go ahead and use it. If your disc contains Windows XP Service Pack 1 or no Service Pack at all, then install Service Pack 2 first, before installing Service Pack 3.

1. IMPORTANT: Apply Service Pack 2 to Windows XP while the computer is safely isolated Before you plug in a network cable or connect to wireless or dial-up, you should install Service Pack 2 before ANYTHING else, even before the video or motherboard driver software.

   • Order a free Service Pack 2 CD from Microsoft You can order this CD-ROM when you order your parts. It usually arrives in about one week. This is a good option if you use dial-up Internet.

   • Another way is to download the entire offline Service Pack 2 installer, and save it on CD before you begin building your computer, so you can install Service Pack 2 offline.

2. Software firewall Once Service Pack 2 is installed, the Windows Firewall will be turned on, to stop worm attacks. If you MUST connect a computer that doesn't have Service Pack 2, then manually enable the Windows Firewall using these instructions. Also use a router (see below), unless it's a dial-up connection.

3. Hardware firewall Use a router between your computer and your modem. It stops worm attacks except from other computers that are connected to the router (wired or wirelessly).

   If you get a router that has wireless, turn the wireless off unless you need it. If you do need the wireless, enable the highest level of encryption that your hardware supports, preferably WPA2. Read the router's instruction manual thoroughly.

   • good budget non-wireless router: Netgear RP614

   • what does a router do for me?

4. Enable Data Execution Prevention completely Right-click My Computer, choose Properties, and do this.

First connection When you first establish a working Internet connection, go to the Microsoft Update site and get Windows fully updated. It will probably take three or four sessions to completely patch a fresh Windows XP installation.