There is a compatibility problem with the WPC54GX with the Dell D600. THe Dell D600 has the latest updated and Windows XP SP2. I updated the PCMICIA drivers from both the Dell and Windows Update web sites. When you insert the WPC54GX into the card slot, you get a PCMCIA event status-id value of "10". I tried removing the Intel Pro 2200B/G card to see if it had any effect. I tried to install the Linksys Client, with the latest version before inserting the card, or inserting the card before installing the client with no effect. I have two WPC54GX cards and they both work in another non Dell PC so the cards are no defective. I do not think is a Network Driver problem, but a PC Card problem, since it is being flagged that way in the System Event log. If I place a SMC 10mbs/100mbs PC Ethernet card in the slot in the Dell D600 it works. Please provide any insights. Thank you.