Before going into the various front-ends you should try to see if you can connect to the access points at all. What kind of encryption are they using? WPA, WEP, ..? WPA is weak, but on the other thand easy to configure. WPA needs a bit more work, but is more secure.
Your machine should have a few programs that actually do the job (the graphical tools are mostly just front-ends I think, so they're not important right now) of connecting. If your wireless device was wlan0
if that doesn't work here), you could check the available access points with
sudo iwlist wlan0 scan
that should produce some output if the card is working at all. After this pick up the ESSID you want to connect to, and if the used security method is WEP encryption, just use
sudo iwconfig wlan0 essid AP_ESSID_HERE key s:AP_KEY_HERE
if you're using ascii passkey (otherwise drop the s: off).
If you use WPA encryption (or anyway) you should follow the ready docs on the net. For example https://help.ubuntu.com/community/WifiDocs/WPAHowTo
It's for Ubuntu, but should work for Kubuntu too as the two are the same OS with different sets of applications - so the only thing that you need to change when reading that howto is probably the graphical tool used to handle the connection.