So, let me drop a little bit of knowledge here.
WEP uses the RC4 mechanism for encryption but was broken in 1997
WPA was a temporary fix for RC4 with some changes but the same hardware, simple WPA passwords are broken using a rainbow table
WPA2 new hardware, new software, WAY harder to break
So, most devices support WEP because they could buy the hardware cheap. It takes a firmware upgrade to use WPA as it is the same hardware it just needs software. WPA2 is all new hardware and if you are having problems you probably need new drivers installed.
Sorry, wifi isn't something I can keep simple as it isn't simple.