Hi,
I have a Sweex 140 Nitro XM Broadband router which I have been using happily unsecured for the last 2 years.
I decided this was silly & logged into the site http://198.168.0.200 Went to Wireless Security tab & enabled WPA.  Then typed in a WEP KEY Generator Passphrase, I made this 23 characters long a mix of letters & numbers.  I THOUGHT I was being so clever.  I then clicked create & some letters & numbers appeared in the Key 1-4 box, I didn't take much NOTICE as a countdown box had appeared & when it got to zero my Internet connection disappeared.  When I try to connect now WINDOWS Vista asks for Security Type, Encryption Type, NETWORK Security Key & Key Index.  Whatever I put in these boxes doesn't work.  I am now connected directly to my Modem through a LAN cable if I attach my wireless router I can't access the internet.  I have unplugged my router & reset it to factory settings but still no access.
I am assuming that I should have written down the info in the Key Boxes & my problem would be solved, but I didn't, can I get my Network Security key from somewhere as I have my passphrase ?  If not has ANYONE any advice. ThanksWEP and WPA are two different types of encryption. 

Usually with WPA, you just type the password you want to use into your router.  Put that same password (along with the SSID) into any laptops and other stuff that will be using your wireless router connection.

Right now, with your router factory-reset'd, wireless may be turned off or it may be reverted back to unsecured with its default SSID (usually the manufacturer's name).