Cannot connect to the internet

I am new to this, so please bear with me on what I am trying to say. Recently, I purchased a used Netgear MR814 wireless "B" router - version 1. It is directly connected to a desktop computer via the ethernet cable. Thus, the desktop receives the internet. I have another desktop (Gateway) computer with a generic USB wireless adapter. This other desktop receives the internet wirelessly from the router using this configuration without a problem. Yet, when I try to access the internet using my Dell D610 laptop (installed & working Intel R Proset 2915ABG network adapter) it does not connect. It can see the signal using either Intel's utility or Windows, yet it won't connect. I have triple checked the WEP access codes for access & still no connection to the internet. I have tried another Dell D610 laptop that uses the identical internal wireless adapter as the first laptop - the Intel 2915ABG - and it does the same thing - it won't connect. Both of these laptops do easily connect to the internet with other wireless routers - Belkin N1, Belkin N, Linksys wireless G, D-Link wireless G, and so on - always without a problem, yet not with this Netgear MR814. I contacted Netgear & they went through and everything is set correctly on the router. They told me the problem is not the router and they felt it must be a compatibility issue with the wireless adapter inside the Dell laptops. Each Dell laptop has Windows XP Pro installed with Service pack 3. All updates are current on each computer per an update utility I installed. Under "Properties" on the advanced tab of the 2915ABG Intel Pro Wireless adapter - each laptop computer is set on B/G at a value of 1. Hardware version is 2.0.15
Any help you could give is most appreciated!

 

Is the laptop set up to use DHCP?

 

Thanks for replying with your question. My answer is I don't know. Unfortunately, wireless is not my thing. I can install a motherboard and an operating system with the drivers, but I am unsure about wireless. So, please forgive my ignorance. How do I tell if the laptop is set up for DHCP? And, should it be?

 

Just an information tidbit - previously, I also contacted Intel customer support. The wireless adapters each Dell D610 laptop features are stock - "came with the computer" - from Dell adapters. They are not adapters I went and purchased somewhere. So, Intel nicely let me know they were not eager to provide product support on my Dell laptops. Yet, they were kind to reply by saying that: "Please be aware that if you are able to connect to a different router it means that the Intel® PRO/Wireless 2915ABG Network Connection is working correctly. Seems that you are experiencing a compatibility problem with your Netgear* MR814 ‘B’ router."