Sydney N said ' but so far I haven't been able to get a filesharing program working"
This does not give us a lot to go on... I do wonder if possibly your isp is trying to stop it's customers, or some of them from filesharing,
.....but unless you can tell us some information about your set up, virus protection, firewalls, exactly what problems you have had, and with which applications and any other details that might be relevant including who your isp, we are a little in the dark.
If you could start a new thread with these details, it might be a good idea, since some of us have seen enough of this thread and usually bypass it!