WUSB54GS — Wireless-G USB Network Adapter with Speedbooster
http://www.linksys.com/products/product.asp?prid=654&scid=36
WUSB11 — Instant Wireless USB Network Adapter – Version 2.6
http://www.linksys.com/products/product.asp?prid=435&scid=36
WUSB12 — Wireless Compact USB Adapter
http://www.linksys.com/products/product.asp?prid=519&scid=36
WUSB54G — Wireless-G USB Network Adapter
http://www.linksys.com/products/product.asp?prid=578&scid=36
WUSB54GP — Wireless-G Portable USB Adapter v1.0
http://www.linksys.com/products/product.asp?prid=612&scid=36
There is a link on each of these pages which will describe how to use the Linksys utility to configure the connection.
Or it could be one of these issues:
Loss of wireless connectivity after applying Windows XP WPA Update
http://linksys.custhelp.com/cgi-bin/linksys.cfg/php/enduser/std_adp.php?p_faqid=712&p_created=1084220000&p_sid=roxu_Nnh&p_lva=&p_sp=cF9zcmNoPTEmcF9zb3J0X2J5PSZwX2dyaWRzb3J0PSZwX3Jvd19jbnQ9MTI1JnBfc2VhcmNoX3R5cGU9c2VhcmNoX25sJnBfcHJvZF9sdmwxPTgmcF9wcm9kX2x2bDI9JnBfc2NmX2xhbmc9MSZwX3BhZ2U9MQ**&p_li=
Jose also talked about an issue that is symptomatic of frequent disconnection. The access point views authentication failures as attack. Installing SP2 fixes this. Need to download “Windows XP Service Pack 2 Network Installation Package for IT Professionals and Developers”
http://www.microsoft.com/downloads/details.aspx?FamilyID=049c9dbe-3b8e-4f30-8245-9e368d3cdb5a&displaylang=en