Wireless connection problem

I do not if this has anything to do with my problem, but I will start here:

Recently my hard drive failed and I bought and had installed another one. Ever since I have had trouble getting my airport to work. Just recently I went into the public library and fired it up to see if it work outside my home (they have free wireless). I would get a connection briefly, then it would shut down and say an error occurred with the connection. This the same scenario happens to me everywhere and every time. Any help with this matter will be much appreciated!!!!