Comcast Cable, Airport Express, Mac, + Windows XP - How to make work?

Question

History:
I have a Mac iBook + (2)Dell Laptops running Windows XP.
Recently, I switched from Verizon DSL to Comcast. New Modem, same router - Airport Express.
Problem - Cable modem to Airport Express to Mac WORK! But, Neither Dell will see a wireless signal. Now, Dell's won't recogize any wireless signals at all. (took to apple store plus Hotspot - nothing) Seems too conincidental that BOTH wifi card would give out at the exact same time I switched to cable.
Previous to the switch to comcast, all worked fine. I know I shut off the broadcast of the SSID prior to the switch, but, thought the Airport was set back to factory default. Current setting of Airport has WEP involked.
Question:
Does anyone know how to get all three Laptops running wirelessly?

Answer 1

Problem - Cable modem to Airport Express to Mac WORK!
But, Neither Dell will see a wireless signal. Now,
Dell's won't recogize any wireless signals at all.
(took to apple store plus Hotspot - nothing)
Most Windows laptops with built-in wireless have a switch which allows them to turn the wireless on and off in order to save battery power.
Ensure that the switch is in the on position.
Previous to the switch to comcast, all worked fine. I
know I shut off the broadcast of the SSID prior to
the switch,
Ensure that it is switched on.
It use to be useful, but closing your Airport or wireless network (sometimes referred to as not broadcasting your SSID) is really no longer a real option when it comes to wireless security.
Unfortunately "Closed" networks, MAC access control lists, and reduction in transmission power are all more "feel good" security rather than real security. All these various approaches are dated and mistakenly lead to overconfidence.
My recommendation is not to worry about broadcasting your SSID but use WPA. This will be more secure than a closed WEP encrypted network. Closing your network makes it very difficult for neighbouring networks to see which channels are free thus causing potential interference problems.
Another thing to consider is that a closed network is still broadcasting and therefore is detectable (regardless of whether it is broadcasting a SSID). If someone was determined to hack into your network, then not broadcasting your SSID and MAC address access control is not going to stop them.
WPA is virtually uncrackable (only really vunerable to a dictionary attack if a real word is used as a password) and therefore will stop the casual user and the determined hacker.
but, thought the Airport was set back to
factory default. Current setting of Airport has WEP
involked.
Accessing a Airport Network with a Windows XP PC or laptop (with XP SP2)
http://www.ifelix.co.uk/tech/1011.html
Accessing a Airport Network with a Windows XP PC or laptop (with XP SP1)
http://www.ifelix.co.uk/tech/1010.html
iFelix