WEP encryption is very weak and easily broken. You should be using WPA, or WPA2 if your router supports it. Once you do that, it should be about as secure as you can make it. Just be sure to use no less than an 8-character password, preferably of random numbers and letters. It also is useful to change the default SSID, even if you disable broadcasting it.
That should keep brute force cracking systems at bay for some time. Probably long enough that any would-be hacker would move onto an easier target.
One thing you'll eventually come to learn, is it's not worth while to put a lot of faith into any information you get from Windows. If all of these things are set on your router, then you should be fine. Of course I wonder how it is you're getting a listing of your network at all when you turned off SSID broadcasting. Is it possible you might be picking up someone else's network?
Hi all. I've recently set up my wireless network and after reading the content of your fine forums, I've been shown why it's so important to protect your network. I have a simple setup with a laptop PC running windows XP, a linksys 200GX wireless router, and a Dell laptop (also running windows XP). So, I've disabled my SSID broadcast, enabled MAC filtering, am using the "WEP" encryption, and have changed the administrative password.
The odd thing is, when I log onto my laptop and try to "view available wireless networks," I get a list of my neighbors networks which are labeled as "security enabled wireless network" but my network states that it is an "unsecured wireless network." Are there other steps I need to take to make my network "security enabled"?
Thanks for you help!

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic