The first thing to try is to disable encryption in the router and the
adapter and see if you can connect. If you can connect without
encryption, this eliminates a variety of problems.
Now set up encryption. Do it first in the router, using a computer
connected to the router with an Ethernet cable to access the router's
configuration utility. Select WPA2-PSK or WPA-PSK. Write down the
passphrase.
Now set up the wireless adapter. How you do this will depend on whether
you are using the configuration utility supplied by the manufacturer of
the wireless adapter or Windows Wireless Zero Configuration. Note that
you should not have both configuration utilities active. See
http://www.ezlan.net/wzc.html
If you still have difficulty, post back with the make & model of both the
router and the adapter. Also state what version and service pack of
Windows XP is on your laptop.
--
Lem -- MS-MVP - Networking
To the moon and back with 2K words of RAM and 36K words of ROM.
http://en.wikipedia.org/wiki/Apollo_Guidance_Computer
http://history.nasa.gov/afj/compessay.htm