acquiring network address forever

I have a Dell Latitude D620 and my wireless isn't working. It worked before but then I had a malware/spyware on my computer that blocked my wifi and when I managed to get the program off, my wifi still wouldn't connect. It's not the wireless card because I bought an external one and it did the same thing. It's not my router because my other computer connects to the internet. Please help, I've been trying to figure this out forever now... :(