Now I cannot say much in this. But I had seen a number of laptops that were facing issue with wifi connectivity. Most of them were due to sleep mode. After waking them up from sleep mode the internet does not work. By manually turning on/off works. Maximum laptops were having nvidia drivers which is famous for compatibility errors with Vista. While XP works like charm. Even though a old operating system, it offers a better compatibility support. I had checked a number of time, that the hardware failed to connected when the laptop come up from sleep mode. It does not means your laptop hardware is a failure. No the issue lies with the operating system you are using.