Intel(R) PROSet/Wireless

Please , I'm begging, somebody PLEASE help me! I can't get anybody to give me a straight answer. I have a Dell Inspiron 9400 with XP. For some reason my online ability just quit working. I went to Best Buy and the guy said my internet card was "fried" and it was old, so I needed to trash my computer. I don't believe that at all. When I click on my PROSet/Wireless icon, my connectivity is working. However the message with a yellow triangle and exclamation mark states, " Intel(R) PROSet/Wireless Software version 11.5.0.0 does not support Intel(R) PRO/Wireless 3945ABG Network Connection device driver version 10.5.1.72 Please either update. Driver to one of the following version(s): 11.1.0.x; 11.1.1.x; 11.2.0.x; 11.5.0.x or install version 10.0.0.x; of Intel(R) PROSet/Wireless software. I can't get online, much less to download anything so I am messaging from my iPad. Will somebody please tell me/instruct me how to resolve this issue? Please email me at <ADMIN NOTE: Email address removed as per privacy policy> with any feedback, instructions, directions, etc., since I can't get online with computer, I will get email thru my phone. Thank you so much Damon