I use a Dell 2010 laptop. I have consistently been able to use wifi. On 1 Jan I moved into a new apartment shared with a friend. My friend allows me to use the wifi by sharing the password. My friend's computer is a MacBook. But I cannot access wifi! Why is that? I am able to see the available connections and to see the one that my friend is using. But I am unable to access it. I tried manually adding the new wifi network. It shows up with "limited access" -- it does not enable use of internet.