unable to connect to wireless internet with Linksys WRT54G

Thanks for responding Steve.

To answer you questions:

Yes the laptop can see the router from the list of wireless networks seen in my neighborhood.  In fact is shows a very strong connection.  And it is broadcasting the SSID.  It actually connects to a very weak open network from my neighbor across the street.

I've used Linksys software to do the connection, I've never tried Windows to manage the connections.

I've checked the MAC address filtering.  I've enable the Wireless MAC Filter and chosen to permit only PC's with specific MAC addresses be allowed to access the network, but still no go.  The Linksys network manager does show the laptop with the correct MAC address.  

Wireless card: 1490 Dual-Band WLAN MiniCard

OS is Win XP SP2.

It did connect wirelessly when I first got the router, but it was intermittent.  Mostly I had to connect using a bit of software loaded from Linksys called "PC Connect".  This went through some steps that wirelessly connected the laptop to the network, as if for the initial setup, which could also be done when wired to the router.  Very strange indeed.

Russell 

Can you see your network (router) from the laptop?  Is your router broadcasting its SSID?  Does it have MAC Address Filtering enabled?  Has the laptop ever been able to connect to your network before?  Which version of Windows is running on the laptop?  Are you using Windows to manage your wireless networks or the utility that came with the network adapter?  Which wireless network adapter is on the laptop?

Steve

Let's try the following.  First temporarily reset the router to its default settings (this will disable the encryption, MAC address filtering and reset the username and password on the router to its default settings.   Have the manual that came with the router handy so you will know the default username and password of the router. 

Now try to connect to this unsecured router.   If that works, go into the router's configuration settings from a computer connected to the router by a wired ethernet connection and change the password to something you will remember, then enable MAC address filtering and enter the MAC address of your Dell wireless adpater into the table of allow MAC addresses.   You can also change the SSID of your router so you can distinguish it from those in the neighborhood.  

Now try the connection from the laptop.  If it works, then go back into the router's configuration utility from the wired computer and enable encryption.   Make sure you write down the encryption key exactly as you enter it.   Now check the wireless connection and make sure you enter the correct encryption key.  

Let me know at which stage of the processes you fail to get an internet connection.

Steve

Ok.  So instead of setting the router to factory default settings, I decided to use the Linksys Advisor to allow no protection of the network (turned off all encryption settings).  The laptop was able to connect quickly and easily (I'm sure my neighbors were able to as well).  I then set the security settings to WEP and typed the encryption key into the laptop's wireless network setup.  That worked too.  For now I'm leaving it alone before I try the WPA encryption (my girlfriend is currently playing a game and I can't get her to let go of it right now).  I guess the problem has been that I have tried to setup the laptop automatically by connecting it with a cable to the router and having Linksys do the setup.  Perhaps manual setup is the only way it will work.  When I try the WPA encryption, I'll let you know if it works or not.  Again thanks for you help.

Russell