What makes you think the problem is software related?
Unless your problem started after something you did to the software, it's probably a hardware failure, in which case you need to bring the laptop in for repair. If you can't find a repair facility for your brand of laptop, then your next plan is to buy a third-party wireless networking PC-Card.
Also, most laptops new enough to have built-in wireless have build-in wired networking (100BaseT) as well. While I doubt any "file fixes" would help you, you could use that to get them onto your system without using the wireless.