newb wireless router questions...

I have a wireless router and sharing broadband with my brother's computer. I do have this firewall (zonealarm). I have a few questions:

1. would novice hackers be able to go into my computer?
2. what's wrong if I leave my wifi unprotected? will my internet become slow if wireless people start free loading me?
3. I have D-link DI-624 router. How do I protect my wifi? I see my encrytion for wireless set at disabled and I dont know how to enable it

any help is greatly appreciated. thanks

1) Yes, hackers can access your network easily.
2) Everything is wrong if you leave your wireless network unprotected, people will start using your internet connection to do whatever they want. Also, if your network is unprotected, a novice computer user may be using your network without knowing it.
3) Log in to your DI-624 to enable it, go to IE and type http://192.168.0.1, login name shoudl be "admin" and passwork should be blank if you haven't set one. go to HOME -> WIRELESS -> make a unique SSID -> select Enable WEP -> WEP set to 128 bits ->type in 26 characters in key 1 (use something easy to start and when you get the hang of it you can change it) -> apply

You will also need to set the WEP on your adaptors, this can be done by opening your connections wizard and inputting the same WEP key in the WEP field, make sure encrystion level is set the same.

I highly recommend setting up MAC address filter as well. This is in the advanced tab.

Hope this works out.

1. People will not be able to get into your computer. Your IP (192.168.x.x) is not accessible from the internet. The only way for someone to get access to your computer is if you use File Sharing and they are within range of your wireless router.

2. You probably won't notice any speed decrease unless your neighbours are using P2P off your wireless connection. If you enable encryption, your WiFi will be slower. But this should not be a reason to disable WEP, WPA etc.

3. You will have to play around with this one.