wireless G security

i have a wrt54g linksys router and one wireless desktop pc with a linksys card. i enabled 128 bit WEP. i also have the option on my router setup screen to use WPA which from what i understand is more secure. i dont think WPA can be configured on my wireless card,or at least i cant find where, just WEP. I have just the 2 pc's on the netowrk using windows xp home and a cable modem. do i need something else to use WPA? driver update for the card or something? or something else? is WEP fine for my network--only 2 PC's, not really any super sensitive data or anything. I just figure i should use WPA if it is more secure but what do I have to do to use it?

thanks for your response. might be a dumb question but do i download the XP patch on my wireless PC or the one connected directly to the router?

and would WEP or WPA have anything to do with my connection? i have very good or excellent signal strength, but after 3-4 minutes i lose my connection. a bubble pops up from the netowrk icon in my task bar saying there is more then one wireless connection available and i lose my connection. i can then reconnect but its a pain because this always happens. could this be the channel i am using or something else? linkysys said try changing the channel but if anyone knows anything else let me know thanks

everything seems to be okay now. i downloaded ms update patch for WPA and enabled WPA. Now everything seems okay and I am not having anymore connection problems. I would have thought it would have been okay with WEP too but for whatever reason I was having problems. Also, with WPA, the 802.1x box is grayed out so I couldn't change it but it looks like it doesn't matter in this case.