How can I get my Win98 laptop to connect to my wireless network?

I have an older laptop running Windows 98, a Linksys wireless PC card and a D-Link wireless router. The card works with my laptop just fine, and even connects to the internet very easily, but only if the router is in its default unencrypted state. I recently set the router to use 64 bit WEP encryption with a HEX key. My XP desktop has no problem with this, but I can't figure out how to make my laptop connect to the encrypted network.