Unable to connect to wireless router

My Netgear router, which has worked OK for 2 years, suddenly quit connecting my Vista laptop with my XP desktop.  I called their tech support, but was unable to resolve the problem; I bought a new Belkin wireless router, connected it properly, and still was unable to connect.  Belkin tech support said there was something wrong with my "inbuilt wireless utility" (whatever that is).  When I am unable to connect to a wireless network, even in WiFi location, I get a message on my laptop that says there is a problem with my network adapter.  I'm not sure how to resolve the problem - is it something I can do myself, or do I need to take my laptop into a repair facility?  I'd appreciate any input I could get.  Thanks, Greg