And leaving it blank won't work, it was changed. My former roomate at another house changed it to WEP but now that I moved, I want to change it back to WPA/WPA2. Please help. and I doubt my ISP will help as I am not usually awake during business hours.
Resetting it to defaults or contacting your old roomate to ask are the only two options I can think of. To reset it to defaults there should be a small pinhole on the device somewhere that you will need to press for usually 10 seconds, then it would be reset to whatever it was from the factory.
1)Turn off your computer
2)Dissconnect your router from the Internet
3)On the back of your router there should be a small hole that is the reset button
4)using a pen press and hold That reset button for 30 seconds
5)connect your computer to your router
After following these steps your router will change to it's default settings so now you should not have problems changing your security settings to WPA/WPA2