Also, since I was able to connect from my laptop with no problem, it led me to believe it was something wrong with my desktop.
Are you receiving an endless "Validating Identity" connection status when trying to connect to a wireless network.
In a few simple steps you can bypass Windows Validation, and the resulting "Limited or No Connectivity" issue on an encrypted connection.
The below guide has been tested on MS Windows XP Professional and is based on Windows' default wireless configuration tool (Wireless Zero Configuration).
Screenshots are taken from Professional version thus may slightly differ from other versions (e.g.
Since I don't want to make matters worse than they are now, I haven't uninstalled the network card yet.
When I put the CD in the computer, and after getting the Starting installation wizard message, a software setup screen then comes up with Select components.2 boxes with check marks on them. I told her that if we don't get this darn thing resolved before Sunday night, I'll just return it to Comcast and try another one. If the modem and the computer are within reasonable proximity, connect them with an ethernet cable.
I thought that at first, perhaps, a virus and/or malware somehow got by and changed/altered the wireless settings, though the antivirus software and Malwarebytes software is up-to-date and is showing no problems. One of these may be doing strange things with the connection. If that does not work it could be a newtork card driver issue. However, before you do that I would advise you to make sure that you have the driver disc for that netcard (or for the notebook if it is an internal Wi Fi netcard), because Windows will often not have built-in drivers for any given netcard.
One way to restore networking, especially wireless, is to go into control panel, system and delete the network card. Since you mentioned that this notebook had previously been setup for multiple wireless profiles, my suggestion would be to delete all existing wireless profiles and see if that allows you to then create a new profile for the Comcast gateway.
In the next window click on the "Authentication" tab, Make sure "Enable IEEE 802.1x...." checkbox is UN-Checked, the rest of this window should be greyed out.