Hi
From the weakest to the strongest, Wireless security capacity is.
No Security
MAC
WEP
WPA-PSK
WPA-AES
WPA2
The documentation of your Wireless devices (Wireless Router, and Wireless
Computers Card) should state the types of security comfigurations that is
available with your Wireless hardware.
All devices MUST be set to the same security level using the same pass
phrase.
Therefore the security must be set according what ever is the best possible
of one of the Wireless devices.
I.e. even if most of your system can be configured to the with WPA2, but one
device is only capable to be configured to a max. of WEP, to whole system
must be configured to WEP.
If you need more good security and one device (like a Wireless card that can
do WEP only) is holding better security for the whole Network, replace the
device with a better one.
Wireless Security -
http://www.ezlan.net/Wireless_Security.html
Jack (MVP-Networking).