Internet wont work for new account

The first account that was made on the computer works fine, but when we tried
to make a second account, I could go on msn, so the internet was obviously
working, but I was not able to open up an internet explorer window AT ALL. It
kept saying the internet explorer was not working, or something like that...
I'm now on the fist account, but it's a little ridicules that I can only have
one account because of this.
Does anyone know what I can do to fix this??