If you’ve read some of my other articles about having an open, unsecured wireless network versus securing your wireless network so that others can not get into it, you know that I believe in security.
I recommend that everyone secure their wireless network to the extent possible. It’s impossible to completely secure a wireless system, but you can block out most users. You can make it difficult for others to use your network.
The point is to make the process hard enough that the visitor — the unauthorized person who is trying to use your network for normal Internet usage or illegal and/or immoral actions — decides to use someone else’s network.
So, first, you never use "peer-to-peer" networking — always use the Infrastructure setting, which means that your computer will only connect to a router or access point. You don’t want it to connect to someone else’s computer directly!
You turn on encryption, set your encryption type to the maximum supported by the wireless equipment you’re going to use, you set a unique SSID for your network, you turn off SSID Broadcasting, you use the MAC filter function of the router to limit the router to only communicating with your network devices.
If you have a wireless printer that does not do WPA or WPA2, get rid of it. Don’t sacrifice the security of your network in order to use the very-breakable WEP encryption method.
There have been a number of changes in wireless security during the time that Windows XP has been available. Most of those were incorporated into XP Service Pack 2 or have been pushed down as "high priority" updates.
Unfortunately, Microsoft did not choose to push the update that adds WPA2 as a high-priority update. Perhaps they made that choice because older hardware wouldn’t support WPA2. Perhaps they did it because the user would still have to change their network settings to use WPA2 — it could not be set to automatically install and be used. After all, you have to set the encryption type on your computer and you also have to set it on your router — otherwise, you just lose connectivity to the router!).
Regardless of the reason, if you knew that you wanted the increased security of WPA2, you needed a recent router, perhaps a firmware upgrade for it to add WPA2 capability, and you needed to download and install the Windows XP WPA2 patch from Microsoft.com.
By the way, if you install XP Service Pack 3, it will add this patch if its missing from your computer. If you aren’t going to add SP3 yet, you can install the patch manually